All Calculators and Tools
Browse every calculator and tool category from one hub. This page is for people who know the task they need to solve but have not picked the exact tool yet, whether that task is estimating a mortgage payment, checking body mass index, converting units, calculating age, measuring a room, or cleaning up a block of text before publishing.
What You'll Find Here
You will find the site grouped by real search intent instead of a flat list of links. Finance covers borrowing, saving, income, and taxes. Health covers calorie, body, pace, and planning tools. Education and math covers schoolwork and number problems. Time and date covers scheduling and calendar questions. Writing, construction, tech, and converter categories cover practical workflows that come up at work, at home, and on the go.
Explore by Category
Finance
Mortgage, loan, compound interest, and financial planning calculators.
Business
Business calculators for margin, markup, ROI, break-even, and discount planning.
Health & Fitness
BMI, calorie, TDEE, macro, and body composition calculators.
Education & Math
GPA, grade, fraction, Roman numeral, and scientific calculators.
Time & Date
Age, date difference, military time, and time zone tools.
Writing & Utility
Writing and utility tools for counting, formatting, and quick text workflows.
Converters
Convert units for length, weight, temperature, and more with fast utility converters.
Construction & Home
Free construction calculators and building material estimators for square footage, concrete, flooring, drywall, paint, roofing, and more.
Tech
Subnet calculator and network utilities.
Tool Highlights
Start with the category that matches the question in plain language. If you need to compare loan payments or retirement savings, open Finance. If you need square footage, concrete volume, or paint coverage, open Construction and Home. If you need a subnet mask, JSON cleanup, unit conversion, or a word count, jump to the matching technical or utility category. The category pages then narrow the choice again with focused tool names and direct links.
- 💰Mortgage, loan, compound interest, and financial planning calculators.
- 📊Business calculators for margin, markup, ROI, break-even, and discount planning.
- ❤️BMI, calorie, TDEE, macro, and body composition calculators.
- 📐GPA, grade, fraction, Roman numeral, and scientific calculators.
- ⏰Age, date difference, military time, and time zone tools.
- ✍️Writing and utility tools for counting, formatting, and quick text workflows.
- 🔁Convert units for length, weight, temperature, and more with fast utility converters.
- 🏠Free construction calculators and building material estimators for square footage, concrete, flooring, drywall, paint, roofing, and more.
- 💻Subnet calculator and network utilities.
All Recently Built Tools
Tip Calculator
Calculate tips fast or split a bill with tip between people. Use this tip calculator to find tip amount, total bill, and tip per person.
Open toolRoman Numeral Converter
Convert whole numbers to Roman numerals and Roman numerals to numbers. Includes standard rules, symbol values, worked examples, and common mistakes.
Open toolRandom Number Generator
Generate a random number in any range for raffles, games, classroom picks, testing, and quick random selection.
Open toolPassword Generator
Create a strong password with custom length, symbols, numbers, and mixed characters. Generate passwords quickly and store them safely.
Open toolSquare Footage Calculator
Calculate square footage instantly for any room or surface. Supports rectangles, circles, and triangles. Free, fast, and accurate area calculator in square feet.
Open toolMortgage Calculator
Use this mortgage calculator to estimate your monthly mortgage payment, total interest, and total cost of a home loan. Includes property tax, insurance, and HOA.
Open toolBMI Calculator
Use this BMI calculator to check your body mass index based on height and weight. Supports metric and US units with instant results and BMI category.
Open toolDate Difference Calculator
Calculate the exact number of days, weeks, months, and years between two dates. Use this date difference calculator for planning, deadlines, and duration tracking.
Open toolGrade Calculator
Find the exact final exam score needed to hit your target course grade based on your current average and the final's weight.
Open toolWord Counter Tool
Count words, characters, sentences, and paragraphs instantly with this free word counter tool.
Open toolAge Calculator
Calculate exact age from date of birth in years, months, and days. Also see total days lived and days until next birthday.
Open toolGPA Calculator
Calculate your weighted GPA by entering course grade points and credit hours. Instant GPA result with total credits and total quality points.
Open toolCompound Interest Calculator
Estimate future value, total invested, total contributions, and interest earned from principal, rate, years, compounding frequency, and recurring deposits.
Open toolMilitary Time Converter
Convert between 12-hour and 24-hour military time instantly, and look up any hour on the full 0000 to 2300 military time chart with AM and PM equivalents.
Open toolConcrete Calculator
Work out how many cubic yards of concrete a slab needs, and how many 40, 60, or 80 lb bags that equals. Includes the bags-per-yard rule.
Open toolMulch Calculator
Work out exactly how many bags or cubic yards of mulch you need from bed size and depth. Includes waste allowance and the bags-per-yard rule.
Open toolGravel Calculator
Work out how many tons or cubic yards of gravel you need from length, width, and depth. Includes the tons-per-yard rule and coverage per ton.
Open toolFuel Cost Calculator
Estimate trip fuel use and total driving cost from distance, fuel efficiency, fuel price, and trip count for commutes, job runs, and road trips.
Open toolRunning Pace Calculator
Calculate running pace, average speed, and finish time from any distance and total time. Useful for 5K, 10K, half marathon, marathon, and training runs.
Open toolSleep Calculator
Use this sleep calculator to estimate bedtime or wake-up options based on 90-minute sleep cycles and a 15-minute fall-asleep buffer.
Open toolSubnet Calculator
Calculate the subnet mask, network address, broadcast address, and usable host range from any IP address and CIDR prefix, with results for IPv4 networks.
Open toolDate Calculator
Find a date 90, 60, 45, or 30 days from today. Add or subtract days, weeks, months, or years from any start date.
Open toolFraction Calculator
Add, subtract, multiply, and divide fractions, then get the simplified fraction plus its decimal result, with clear steps for each fraction operation.
Open toolInflation Calculator
Use this inflation calculator to estimate future cost, price increases, and purchasing power loss based on a fixed annual inflation rate.
Open toolPaycheck Calculator
Estimate your 2026 take-home pay from hourly rate, regular hours, overtime, and taxes. See gross pay, tax amount, and net pay in one quick breakdown.
Open toolCredit Card Payoff Calculator
Estimate how long it takes to pay off credit card debt and how much interest you will pay, based on your balance, interest rate, and monthly payment.
Open toolTDEE Calculator
Calculate your TDEE and BMR with the Mifflin-St Jeor equation from weight, height, age, sex, and activity level, then plan daily calories for any goal.
Open toolMacro Calculator
Calculate your daily macro targets in grams for protein, carbs, and fat from your calorie goal and chosen macro split, for any diet or training plan.
Open toolBody Fat Calculator
Estimate your body fat percentage from weight, height, age, and sex using a formula-based method, with a result and category for quick reference.
Open toolIdeal Weight Calculator
Estimate ideal body weight from height and sex with the Devine formula. See a practical range in kg or lb and learn how to read the result.
Open toolTime Zone Converter
Convert date and time between UTC offsets quickly. Useful for remote meetings, travel planning, and international scheduling.
Open toolPercentage Calculator
Calculate percentages quickly: percent of a number, what percent one value is of another, and percent increase or decrease.
Open toolCalorie Calculator
Estimate your daily calorie needs from age, sex, height, weight, activity level, and goal, for maintaining, losing, or gaining weight at a steady rate.
Open toolLoan Calculator
Estimate monthly loan payments, total interest, and total cost using your loan amount, interest rate, and repayment term.
Open toolRetirement Calculator
Estimate retirement savings growth based on current savings, monthly contributions, expected return, and retirement age.
Open toolScientific Calculator
Evaluate arithmetic expressions with decimals, parentheses, and percentages using this online scientific calculator for quick homework, shopping, and everyday math.
Open toolCurrency Converter
Convert between USD, EUR, GBP, PKR, INR, and AED using clear reference rates. Useful for travel budgets, freelance invoices, online shopping, and quick price comparisons.
Open toolPregnancy Due Date Calculator
Use this pregnancy due date calculator to estimate your delivery date from the first day of your last menstrual period, with an estimated conception date and plain-language notes.
Open toolOvulation Calculator
Estimate ovulation date, fertile window, and next period date using last period date and cycle length.
Open toolTime Calculator
Add or subtract hours and minutes from any start time to get the exact end time, with a note when the result crosses into another day.
Open toolHours Calculator
Use this hours calculator to find hours and minutes between two times, subtract breaks, and handle overnight shifts with clear examples.
Open toolCharacter Counter
Use this character counter to instantly count characters, characters without spaces, words, and lines.
Open toolSentence Counter
Count sentences, words, and paragraphs instantly for essays, reports, emails, blog drafts, and editing reviews with punctuation-based results.
Open toolUnit Converter
Use this unit converter to convert values across length, weight, and temperature units quickly and accurately.
Open toolLength Converter
Convert mm to inches, inches to feet, cm to feet, km to miles, and meters to feet. Free length converter for metric and imperial units.
Open toolWeight Converter
Convert kilograms, pounds, grams, milligrams, and ounces with clear formulas, worked examples, and practical weight conversion tips.
Open toolTemperature Converter
Convert Celsius to Fahrenheit or Fahrenheit to Celsius instantly. Also supports Kelvin. Free C to F and F to C converter.
Open toolJSON Formatter
Use this free JSON formatter to validate, beautify, and minify JSON in your browser with clear syntax feedback and no server upload.
Open toolInvestment Calculator
Use this investment calculator to estimate future portfolio value from initial amount, recurring contributions, and projected return rate.
Open toolVolume Converter
Convert liters, milliliters, cups, fluid ounces, quarts, and gallons with clear formulas, worked examples, and practical kitchen and storage guidance.
Open toolArea Converter
Convert square feet, square meters, acres, hectares, and other common area units with clear formulas, worked examples, and practical planning notes.
Open toolSpeed Converter
Use this speed converter to convert mph, km/h, m/s, knots, and ft/s quickly with standard conversion factors.
Open toolData Storage Converter
Use this data storage converter to convert bytes, decimal KB/MB/GB/TB, and binary KiB/MiB/GiB/TiB units.
Open toolCase Converter
Use this case converter to transform text into upper case, lower case, title case, sentence case, camelCase, snake_case, and more.
Open toolReading Time Calculator
Use this reading time calculator to estimate how long content takes to read based on word count and words-per-minute assumptions.
Open toolURL Encoder Decoder
Use this URL encoder decoder to safely encode or decode URL components and handle invalid encoded input clearly.
Open toolBase64 Encoder Decoder
Encode text to Base64 or decode Base64 back to UTF-8 text. Useful for API payload checks, auth headers, data URLs, and quick debugging in the browser.
Open toolQR Code Generator
Create a downloadable QR code from text or a URL, choose a size, and check input length before you share or print it.
Open toolAmortization Calculator
Use this amortization calculator to estimate monthly payment, total interest, and a fixed-rate loan payoff schedule from loan amount, rate, and term.
Open toolAuto Loan Calculator
Use this auto loan calculator to estimate car loan monthly payment, total interest, and total cost using price, down payment, rate, term, tax, and fees.
Open toolSavings Calculator
Use this savings calculator to estimate future savings balance from starting amount, monthly contributions, interest rate, and compounding frequency.
Open toolCD Calculator
Use this CD calculator to estimate certificate of deposit maturity value from deposit amount, APY, term length, and compounding frequency.
Open toolSalary Calculator
Convert gross pay into annual, monthly, and weekly salary by pay frequency. Get a fast, free estimate with a clear breakdown.
Open toolHourly to Salary Calculator
Use this hourly to salary calculator to convert hourly wage into estimated annual, monthly, and weekly gross salary using hours and weeks worked.
Open toolSalary to Hourly Calculator
Convert annual salary to an hourly rate using your real hours and weeks worked. Includes a salary-to-hourly chart from $30,000 to $100,000.
Open toolOvertime Calculator
Calculate overtime pay and your time-and-a-half rate from any hourly wage. Enter regular hours, overtime hours, and the multiplier to see total gross pay.
Open toolPay Raise Calculator
Calculate your new salary after a raise. Enter your current pay and the raise percentage to see your new pay, the dollar increase, and the change per paycheck.
Open toolRule of 72 Calculator
Use the Rule of 72 to estimate how long an investment takes to double. Enter your annual return to see the years to double, the exact figure, and the time to triple.
Open toolDebt Payoff Calculator
Use this debt payoff calculator to estimate payoff time, total interest, and total cost from your balance, APR, and planned monthly payment.
Open toolBMR Calculator
Use this BMR calculator to estimate basal metabolic rate with the Mifflin-St Jeor formula based on sex, age, height, and weight.
Open toolProtein Calculator
Use this protein calculator to estimate daily protein intake from body weight, unit choice, and a maintenance, build, or cut goal.
Open toolWater Intake Calculator
Use this water intake calculator to estimate daily hydration from body weight, activity minutes, and climate assumptions in liters, milliliters, and ounces.
Open toolOne Rep Max Calculator
Use this one rep max calculator to estimate 1RM from lifted weight and reps using the Epley formula.
Open toolProfit Margin Calculator
Calculate profit margin from revenue and cost. Revenue of $500 with $350 in costs gives $150 profit and a 30% margin.
Open toolMarkup Calculator
Use this markup calculator to estimate markup amount, markup percentage, and margin from cost and selling price.
Open toolBreak Even Calculator
Use this break even calculator to estimate break-even units and break-even revenue using fixed costs, variable cost per unit, and selling price.
Open toolROI Calculator
Use this ROI calculator to find net return and return on investment percentage from your total gain and total cost, with a clear breakdown of the result.
Open toolDiscount Calculator
Use this discount calculator to estimate sale price and savings from a discount percentage or discount amount.
Open toolBusiness Days Calculator
Use this business days calculator to count business days between dates with weekend handling and optional holiday exclusions.
Open toolCalories Burned Calculator
Use this calories burned calculator to estimate calories burned from activity, body weight, duration, and MET assumptions.
Open toolHeart Rate Zone Calculator
Use this heart rate zone calculator to estimate training heart rate zones using age-based max heart rate and optional resting heart rate.
Open toolBandwidth Calculator
Use this bandwidth calculator to estimate required bandwidth from data size and transfer time with unit conversion support.
Open toolDownload Time Calculator
Use this download time calculator to estimate transfer time from file size and connection speed with unit conversion support.
Open toolAOV Calculator
Use this AOV calculator to estimate average order value from total revenue and total orders, then review worked examples, formula notes, and common reporting mistakes.
Open toolConversion Rate Calculator
Use this conversion rate calculator to calculate CVR from visitors and conversions with clear steps, formula notes, and worked examples.
Open toolCPC Calculator
Use this CPC calculator to find your average cost per click from total ad spend and clicks, then compare the result with conversion rate and profit targets.
Open toolCPM Calculator
Use this CPM calculator to estimate cost per thousand impressions from ad spend and impressions.
Open toolROAS Calculator
Use this ROAS calculator to estimate return on ad spend ratio and percentage from attributed revenue and ad spend.
Open toolACV Calculator
Calculate annual contract value (ACV) from total contract value and term in months, so you can compare SaaS deals of any length.
Open toolData Transfer Calculator
Use this data transfer calculator to estimate transfer time, required speed, or transferable size with explicit unit assumptions.
Open toolIP Address Calculator
Use this IP address calculator to analyze any IPv4 address, including its binary form, integer value, address class, and common private or reserved ranges.
Open toolCIDR Calculator
Use this CIDR calculator to turn IPv4 CIDR notation into a subnet mask, network address, broadcast address, and usable host range in one step.
Open toolBinary Calculator
Add, subtract, multiply, or divide binary numbers and see the result in both binary and decimal with clear examples, limits, and base-2 math notes.
Open toolHex Calculator
Calculate hexadecimal addition, subtraction, multiplication, and integer division. Accepts optional 0x prefixes and shows both hex and decimal results.
Open toolHours Worked Calculator
Use this hours worked calculator to calculate shift duration, break deductions, decimal hours, and optional overtime hours.
Open toolCountdown Calculator
Count down to any date or holiday. One tap shows the days until Halloween, Christmas, Thanksgiving, Easter, and more, with a day, hour, minute, and second breakdown.
Open toolUUID Generator
Generate UUIDs in your browser with this UUID generator. Client-side generation only, with UUID v4 support.
Open toolHash Generator
Generate SHA-1, SHA-256, SHA-384, and SHA-512 hashes client-side. Hashes are one-way and not encryption.
Open toolAspect Ratio Calculator
Use this aspect ratio calculator to simplify width and height, compare common screen ratios, and resize images or video dimensions without stretching the frame.
Open toolDPI Calculator
Calculate DPI or PPI from pixels and physical size, then use the result to judge monitor sharpness, print size, poster quality, and image scaling assumptions.
Open toolPaint Calculator
Estimate paint needed for a rectangular room from wall size, coats, coverage rate, doors, windows, and waste allowance. Returns gallons, liters, and net wall area.
Open toolTile Calculator
Estimate tile count, coverage, and waste for floors, showers, backsplashes, and other tile layouts using room size and tile dimensions.
Open toolFlooring Calculator
Estimate room area, waste-adjusted flooring coverage, and full boxes to order for laminate, hardwood, vinyl plank, or tile flooring projects.
Open toolCalorie Deficit Calculator
Estimate daily calorie targets from BMR, activity level, and a selected deficit percentage with clear assumptions and realistic planning guidance.
Open toolDay of Week Calculator
Use this day of week calculator to find the weekday for a selected date, including ISO weekday number.
Open toolDeck Mud Calculator
Find how much deck mud you need from square feet and thickness. Returns mud volume plus sand and Portland cement bags using the 5-to-1 floor mud recipe.
Open toolBoard Foot Calculator
Calculate board feet from thickness, width, and length, plus total cost per board foot. Includes a chart of board feet for common lumber sizes like 2x6x8.
Open tool401(k) Calculator
Project your 401(k) balance at retirement, including employer match. See how much comes from your contributions, the company match, and investment growth.
Open toolMortgage Refinance Calculator
See if refinancing your mortgage is worth it. Compare your current payment with a new rate, find your monthly savings, and get the break-even point in months.
Open toolRent vs Buy Calculator
Compare the full cost of renting against buying a home over the years you plan to stay. See which is cheaper, your total cost each way, and the break-even picture.
Open toolNet Worth Calculator
Calculate your net worth by adding up what you own and subtracting what you owe. See your total assets, total debts, and how you compare by age.
Open toolClosing Costs Calculator
Estimate buyer closing costs on a home by price and down payment. See your total fees, what percent of the price they are, and total cash to close.
Open toolStair Calculator
Calculate how many steps you need, adjusted riser height, total run, stair angle, and stringer length. Enter your floor-to-floor height and target riser dimensions.
Open toolDrywall Calculator
Calculate how many drywall sheets you need for any room. Enter wall length, height, and openings to get an accurate sheet count with waste allowance.
Open toolFence Calculator
Calculate how many posts, rails, and pickets you need for a wood fence. Enter fence length, height, and spacing to get a full materials list.
Open toolGrass Seed Calculator
Calculate how many pounds and bags of grass seed your lawn needs. Covers new seeding and overseeding rates with a built-in waste allowance.
Open toolStud Calculator
Calculate how many wall studs you need for any wall length at 16 or 24 inch on-center spacing. Includes extras for corners and openings, plus plate lumber totals.
Open toolRoofing Calculator
Estimate roof area, roofing squares, and shingle bundles for any roof size and pitch. Adds a waste factor and an optional shingle cost so you can order the right amount.
Open toolBrick Calculator
Estimate how many bricks you need for a wall from its length, height, and brick size. Adds a waste factor and an optional cost per brick so you can order with confidence.
Open toolSubfloor Calculator
Calculate how many sheets of plywood or OSB subfloor you need for any room. Enter the room size and sheet size to get a sheet count with waste included.
Open toolInsulation Calculator
Calculate how many bags or rolls of insulation you need for an attic, wall, or floor. Enter the area and the coverage per bag to get a bag count with waste.
Open toolPaver Calculator
Calculate how many pavers you need for a patio or walkway from your area and paver size, with a waste allowance for cuts and breakage.
Open toolSales Tax Calculator
Calculate sales tax on any purchase, or work backward to find the pre-tax price from a tax-inclusive total. Enter the amount and your local tax rate.
Open toolRandom Name Generator
Generate random first names, last names, or full names with a gender filter. Pick how many you want, from 1 to 50, for characters, testing, and ideas.
Open toolHome Affordability Calculator
Estimate how much house you can afford based on your income, debts, down payment, and interest rate. Uses the 28/36 rule to show your max home price and monthly payment.
Open toolDebt-to-Income Ratio Calculator
Calculate your debt-to-income ratio from your gross monthly income and debt payments. See your DTI percentage and how lenders rate it for loan approval.
Open toolCTR Calculator
Calculate click-through rate from clicks and impressions. See your CTR as a percent plus clicks per 1,000 impressions for ads, email, and search.
Open toolCommission Calculator
Calculate sales commission from your revenue and commission rate. See commission, total earnings with a base salary, and commission per $1,000 of sales.
Open toolCooking Measurement Converter
Convert cups to ounces, ounces to cups, grams to cups, and more. Free cooking measurement converter for cups, tablespoons, teaspoons, fluid ounces, and grams.
Open toolCircle Calculator
Calculate the area of a circle, circumference of a circle, and diameter from a radius or diameter. Free circle calculator with step-by-step formulas.
Open toolHeight Converter
Convert height from feet and inches to centimeters, or cm to feet and inches. Free height converter for body height using the 2.54 cm per inch standard.
Open toolTime Clock Calculator
Use this time clock calculator to add up clock-in and clock-out times across the week, deduct breaks, and get total hours, overtime, and gross pay.
Open toolRoth IRA Calculator
Use this Roth IRA calculator to project your retirement balance from your age, current savings, yearly contribution, and expected annual return.
Open toolDistance Formula Calculator
Find the straight-line distance between two points on a coordinate plane. Enter the x and y values for both points and get the distance using d = sqrt((x2-x1)^2 + (y2-y1)^2).
Open toolAverage Calculator
Find the mean, median, mode, and range of any number set. Paste comma or space separated numbers and get the average plus count, sum, min, and max.
Open toolCylinder Calculator
Calculate the volume and surface area of a cylinder from its radius and height. Free cylinder calculator that also returns lateral surface area and base area.
Open toolDog Age Calculator
Convert your dog's age into human years with a size-adjusted method. Enter your dog's age and breed size to get an estimated human age and life stage.
Open toolAnnual Income Calculator
Convert pay from hourly, daily, weekly, biweekly, semimonthly, or monthly into annual income. See your yearly, monthly, and weekly figures with one calculator.
Open toolSteps to Miles Calculator
Convert steps to miles, kilometers, and feet based on your stride length. Find out how many miles 10,000 steps is and how many steps are in a mile.
Open toolMinutes to Hours Converter
Convert minutes to hours fast. Enter a number of minutes to get the decimal hours, an hours-and-minutes breakdown, seconds, and days.
Open toolSquare Root Calculator
Find the square root of any non-negative number. Enter a value to get the principal square root, the negative root, and whether the number is a perfect square.
Open toolMidpoint Calculator
Find the midpoint between two points on a coordinate plane. Enter the x and y values for both points and get the midpoint using M = ((x1 + x2) / 2, (y1 + y2) / 2).
Open toolSlope Calculator
Find the slope of a line between two points using m = (y2 - y1) / (x2 - x1). Enter both points to get the slope, rise, run, angle, y-intercept, and the line equation.
Open toolWeeks in a Month Calculator
Find how many weeks are in a month. Pick any month and year to get the exact weeks as a decimal plus a whole-weeks-and-days breakdown.
Open toolHours in a Week Calculator
There are 168 hours in a week. Use this calculator to convert any number of weeks into hours, days, minutes, and seconds.
Open toolRectangular Prism Calculator
Calculate the volume, surface area, and diagonal of a rectangular prism. Enter length, width, and height to get all results at once.
Open toolHeat Index Calculator
Find the heat index from temperature and humidity. Enter the air temperature in Fahrenheit and the relative humidity to get the feels-like temperature and risk level.
Open toolRight Triangle Calculator
Solve a right triangle from its two legs. Get the hypotenuse, area, perimeter, and both acute angles using the Pythagorean theorem.
Open toolScientific Notation Converter
Convert any number to scientific notation. Enter a value to get the coefficient, the power of ten exponent, and the E-notation form.
Open toolLong Division Calculator
Divide two numbers to get the quotient, remainder, and decimal answer. Enter a dividend and divisor to solve the division.
Open toolMoney Counter
Count cash fast. Enter how many of each US bill and coin you have to get the total, the bills subtotal, and the coins subtotal.
Open toolWeeks Left in the Year Calculator
Find how many weeks are left in the year from any date. Get the weeks remaining as a decimal, a weeks-and-days breakdown, and how much of the year is done.
Open toolColor Mixer
Mix two colors and see the result as a hex and RGB value. Set the blend ratio, learn the primary colors, and find what two colors make purple, green, or orange.
Open toolLove Compatibility Calculator
Enter two names and get a fun love compatibility score from 0 to 99. A quick name-based compatibility test for couples, crushes, and friends, just for fun.
Open toolWeeks in a Year Calculator
Find how many weeks are in a year. A normal year has 52.14 weeks and a leap year has 52.29 weeks. Enter any year for the exact weeks-and-days breakdown.
Open toolBinary Translator
Translate text to binary and binary back to text. Each character becomes an 8-bit binary group using UTF-8, so accents and emoji convert correctly.
Open toolMonthly Calendar Generator
Make a printable calendar for any month and year. Pick the month, set the week to start on Sunday or Monday, and print or save a clean monthly grid.
Open toolSeasons Calculator
Find when each season starts in any year. See the first day of spring, summer, fall, and winter by the astronomical or meteorological calendar, for either hemisphere.
Open toolWorld Clock
See what time it is right now in any city. Live clocks for New York, London, Tokyo, Dubai, Arizona, Hawaii, and more, with the current UTC offset for each.
Open toolTime Unit Converter
Convert between seconds, minutes, hours, days, weeks, and years. See how many seconds are in a year or a day, and switch any time unit to another instantly.
Open toolAngle Converter
Convert angles between radians, degrees, and gradians. Turn radians to degrees or degrees to radians instantly, with the exact pi-based relationship.
Open toolFraction to Decimal Converter
Convert a fraction to a decimal or a decimal to a simplified fraction. Enter 3/4 to get 0.75, or 0.75 to get 3/4, with the answer reduced for you.
Open toolmcg to mg Converter
Convert micrograms (mcg) to milligrams (mg) and back. 1 mg equals 1000 mcg, so 500 mcg is 0.5 mg. Convert mcg, mg, and grams for supplement and dosage labels.
Open toolStandard Deviation Calculator
Calculate sample or population standard deviation from any list of numbers. Get the standard deviation plus variance, mean, count, and sum in one step.
Open toolQuadratic Formula Calculator
Solve any quadratic equation ax^2 + bx + c = 0 with the quadratic formula. Enter a, b, and c to get both roots, the discriminant, and the nature of the solutions.
Open toolColor Converter
Convert any color between HEX, RGB, and HSL. Paste a hex code, an rgb value, or an hsl value and get all three formats back, with a live color swatch.
Open toolRandom Wheel
Add your options one per line, spin the wheel, and land on one at random. A free spin-the-wheel picker for names, lunch spots, prizes, and quick decisions.
Open toolSimple Interest Calculator
Calculate simple interest on a loan or deposit from principal, annual rate, and time in years. See total interest, final balance, and monthly equivalent.
Open toolmm to Inches Converter
Convert millimeters to inches and back. 1 inch is exactly 25.4 mm, so 100 mm is about 3.937 inches. Also converts cm and meters.
Open toolInches to Feet Converter
Convert inches to feet and back. 12 inches equals 1 foot, so 66 inches is 5.5 feet or 5 ft 6 in. Also shows the feet and inches breakdown.
Open toolkm to Miles Converter
Convert kilometers to miles and back. 1 km is about 0.621 miles, so 10 km is 6.21 miles and a marathon is 42.2 km. Also converts meters.
Open toolcm to Feet Converter
Convert centimeters to feet and back. 30.48 cm equals 1 foot, so 170 cm is 5.58 feet or 5 ft 6.9 in. Shows the feet and inches breakdown.
Open tooloz to lbs Converter
Convert ounces to pounds and back. 16 oz equals 1 lb, so 24 oz is 1.5 lbs or 1 lb 8 oz. Also converts grams and kilograms.
Open toolTest Grade Calculator
Enter total questions and how many were missed to get the test score and letter grade. Missing 3 of 20 questions scores 85%, a B.
Open toolPercentage Increase Calculator
Calculate percentage increase or decrease between two numbers. Going from 100 to 125 is a 25% increase. Shows the change and direction.
Open toolmg to ml Converter
Convert mg to ml and ml to mg using density or concentration. For water, 500 mg is 0.5 ml. For a 50 mg/ml medicine, 125 mg is 2.5 ml.
Open tooloz to Cups Converter
Convert fluid ounces to cups and back. 8 fl oz equals 1 cup, so 12 oz is 1.5 cups. Also converts tablespoons, teaspoons, and ml.
Open toolml to oz Converter
Convert milliliters to US fluid ounces, cups, and liters with clear formulas, worked examples, bottle-size references, and practical kitchen and drink-size tips.
Open toolNm to Ft-Lbs Converter
Convert nm to ft lbs and back. 1 Nm is about 0.7376 ft-lbs, so 100 Nm is 73.76 ft-lbs. Also converts inch-pounds for smaller torque specs.
Open toolBirth Year Calculator
Find out what year you were born from your current age. If you are 25 in 2026 and your birthday has passed, you were born in 2001. Shows both possibilities.
Open toolSteps to Calories Calculator
Use this steps to calories calculator to estimate calories burned from your step count and body weight. 10,000 steps burns about 400 calories.
Open toolVO2 Max Calculator
Estimate your VO2 max from age and resting heart rate. A 30-year-old with a resting heart rate of 60 has an estimated VO2 max of about 48.5 mL/kg/min.
Open toolLottery Tax Calculator
Estimate your lottery take-home pay after federal and state tax. Compare the lump-sum cash value against the full annuity payout for any jackpot.
Open toolPixels to Inches Converter
Convert pixels to inches or inches to pixels with a chosen DPI or PPI. Also shows the equivalent size in centimeters.
Open toolCrore to Million Converter
Convert crore to million fast, with lakh and billion support built in. See how Indian and international number units line up using the standard short-scale system.
Open toolCAGR Calculator
Use this CAGR calculator to find compound annual growth rate from a starting value, ending value, and time period in years.
Open toolWaist-to-Hip Ratio Calculator
Use this waist-to-hip ratio calculator to divide waist by hip size and classify the result with standard adult risk bands for men and women.
Open toolRoof Pitch Calculator
Convert roof rise and run into pitch per 12, slope percent, and roof angle in degrees. Use it for quick framing and roofing layout checks.
Open toolLottery Annuity Calculator
Estimate annual pre-tax lottery annuity payments from any jackpot. Choose a payout term to see yearly payout, average monthly payout, and total annuity value.
Open toolPowerball Payout Calculator
Estimate Powerball lump-sum cash value, 30-payment annuity payouts, and after-tax results using federal tax plus an optional state tax rate.
Open toolBasis Point Calculator
Use this basis point calculator to convert bps, percent, and decimal rates, then add or subtract a basis point move from a starting rate.
Open toolAPY Calculator
Use this APY calculator to convert APR and compounding frequency into APY. See your effective annual yield, ending balance, and one-year interest on a deposit.
Open toolPrice Per Square Foot Calculator
Calculate price per square foot from a home's price and area, or reverse the math to estimate total price from square footage and a target $ per square foot.
Open toolYear-over-Year Growth Calculator
Compare a current value with the previous year to calculate the absolute change and year-over-year growth or decline percentage.
Open toolkg to liter Converter
Convert kg to liters and liters to kg using density. 1 kg of water is 1 L, 1 kg of milk is about 0.971 L, and 2 L of oil is about 1.84 kg.
Open toolMillion to Lakh Converter
Convert million to lakh and lakh to million in one step. See the converted value plus the raw number, so 1 million = 10 lakh = 1,000,000.
Open toolPennies to Dollars Converter
Convert pennies to dollars and dollars to pennies. 100 pennies equals $1, so 250 pennies is $2.50 and $5 is 500 pennies. Includes penny roll counts.
Open toolml to kg Converter
Convert ml to kg and kg to ml using liquid density. 1000 ml of water is 1 kg, while 1000 ml of honey is about 1.42 kg. Includes common presets and custom density.
Open toolGrams to mL Converter
Use this grams to ml converter to switch between mass and volume with the right density. Convert water, milk, olive oil, honey, maple syrup, dish soap, or a custom g/ml value.
Open toolInches to Fraction Converter
Convert decimal inches to the nearest fractional inch in 1/2, 1/4, 1/8, 1/16, 1/32, or 1/64 steps. Also turn a mixed fraction like 2 5/16 into decimal inches.
Open toolMonths to Years Converter
Convert months to years and years to months with the exact 12 months per year rule. See decimal years and a years-and-months breakdown for values like 18 and 24 months.
Open toolkg to Stone Converter
Convert kilograms to stone and pounds and back. 70 kg is 11.02 st or 11 st 0.32 lb, and 12 st is 76.2 kg.
Open toolmmol/L to mg/dL Converter
Convert blood glucose from mmol/L to mg/dL and back with the glucose factor of 18.0182. Includes worked examples, a quick table, and a cholesterol warning.
Open toolWaist-to-Height Ratio Calculator
Use this waist-to-height ratio calculator to divide waist by height, see the result as a ratio and percent, and compare it with adult screening bands.
Open toolWeight Gain Calculator
Estimate calorie surplus, projected weekly weight gain, and time to goal from maintenance calories, target intake, and your current and target weight.
Open toolPonderal Index Calculator
Use this ponderal index calculator to estimate adult body proportionality from height and weight in metric or US units, with a broad adult reference band and plain-language interpretation.
Open toolFraming Calculator
Estimate studs, plates, and total linear feet for a wall or simple rectangular room. Enter wall size, height, spacing, and openings for a fast framing takeoff.
Open toolPipe Volume Calculator
Calculate pipe volume from inside diameter and pipe length. Get internal volume in cubic feet, US gallons, and liters for plumbing, irrigation, and water storage runs.
Open toolRiver Rock Calculator
Estimate cubic yards, tons, and bag count for river rock from area, depth, density, and waste. Useful for planting beds, borders, dry creek beds, and drainage areas.
Open toolSand Calculator
Estimate cubic feet, cubic yards, tons, and bag count for sand from area and depth. Includes dry-sand density assumptions for patios, pavers, and sandbox fills.
Open toolRebar Calculator
Estimate rebar count and total linear feet for a simple slab grid. Enter slab length, width, spacing, and optional waste to get bars each way.
Open toolSonotube Concrete Calculator
Estimate sonotube concrete volume and bag counts from tube diameter, hole depth, and number of holes. Includes 40, 50, 60, and 80 lb bag options for deck footing pours.
Open toolMonthly Income Calculator
Convert hourly, daily, weekly, biweekly, semimonthly, monthly, or annual pay into monthly income. Get a clear gross monthly estimate with common schedule conversions.
Open toolMega Millions Payout Calculator
Estimate Mega Millions lump-sum cash value, 30-payment annuity payouts, and after-tax results using federal tax plus an optional state tax rate.
Open toolBiweekly Pay Calculator
Use this biweekly pay calculator to convert an hourly wage or annual salary into gross biweekly pay. See annual, monthly, and weekly equivalents with a paid-weeks assumption.
Open toolAppreciation Calculator
Use this appreciation calculator to project a home, car, or other asset value forward with a fixed annual appreciation rate and timeline.
Open toolRate of Return Calculator
Use this rate of return calculator to find total return from a starting value, ending value, and optional income. Add years held to estimate annualized return.
Open toolStock Average Calculator
Use this stock average calculator to combine multiple share purchases into one average cost per share, total shares, and total cost basis.
Open toolCap Rate Calculator
Calculate cap rate from annual NOI and property value, or reverse the math to estimate property value from NOI and a target cap rate.
Open toolHours to Days Converter
Convert hours to calendar days, workdays, and back. Use the 24-hour day rule or set a custom workday length like 7.5, 8, 10, or 12 hours.
Open toolCubic Feet Converter
Convert cubic feet to liters, US gallons, cubic yards, and cubic meters. Includes clear formulas, worked examples, and quick reference values.
Open toolNumber to Million Converter
Convert a plain number to million and million to a plain number. See the full count beside the shorthand, so 2,500,000 = 2.5 million.
Open toolGallons to Pounds Converter
Convert US gallons to pounds and pounds to gallons using liquid density. 1 gallon of water weighs about 8.34 lb, while 1 gallon of honey is about 12 lb.
Open tooltbsp to ml Converter
Convert US tablespoons to milliliters and back. 1 US tbsp equals exactly 14.78676478125 ml, so 2 tbsp is 29.57 ml and 4 tbsp is 59.15 ml.
Open toolMillion to Billion Converter
Convert million to billion and billion to million in one step. See the converted value plus the full number, so 250 million = 0.25 billion = 250,000,000.
Open toolQuarts to Cups Converter
Convert US quarts to cups and cups to quarts. 1 US quart equals 4 cups, so 3 quarts is 12 cups and 6 cups is 1.5 quarts. Includes pint and gallon equivalents.
Open toolml to Cups Converter
Convert milliliters to US cups and back. 1 US cup is 236.588 ml, so 500 ml is 2.11 cups. Also shows liters and US fluid ounces for recipe and bottle conversions.
Open toolHarris-Benedict Calculator
Use the Harris-Benedict calculator to estimate BMR and TDEE with the revised 1984 Harris-Benedict equation and standard activity multipliers.
Open toolRMR Calculator
Use this RMR calculator to estimate resting metabolic rate with the Revised Harris-Benedict equation from age, sex, height, and weight.
Open toolmcg to IU Converter
Convert mcg to IU and IU to mcg for vitamin D, vitamin A retinol, and natural or synthetic vitamin E. Includes label warnings because IU is substance specific.
Open toolIQ Percentile Calculator
Convert an IQ score into an approximate percentile by using a mean of 100 and a selectable standard deviation of 15 or 16, with plain-language notes about the bell-curve model.
Open toolDrops Per Minute Calculator
Estimate a gravity IV drip rate in drops per minute from volume, infusion time, and tubing drop factor. Includes macrodrip and microdrip examples and safety limits.
Open toolSquare Meter Calculator
Calculate square meters from room length and width in meters, then see the same area in square feet for flooring, paint, and material planning.
Open toolPipe Weight Calculator
Estimate pipe weight from outside diameter, wall thickness, length, and material density. Get total pipe weight in pounds and kilograms plus linear weight for steel and other materials.
Open toolRamp Slope Calculator
Convert ramp rise and run into slope ratio, percent grade, and angle. Includes a clear 1:12 ADA-style planning reference note for early layout checks.
Open toolRoof Shingle Calculator
Estimate roofing squares and shingle bundles from measured roof area or simple roof dimensions. Add optional waste to plan a more realistic asphalt shingle order.
Open toolTurnover Rate Calculator
Calculate employee turnover rate from separations and average headcount over the same period. Use the standard HR formula and keep your assumption consistent.
Open toolExpense Ratio Calculator
Calculate a mutual fund or ETF expense ratio from annual fund expenses and average assets, or estimate your annual dollar cost from the published ratio and your balance.
Open toolCar Depreciation Calculator
Use this car depreciation calculator to estimate future vehicle value from the car's current value, annual depreciation rate, and number of years.
Open toolYield to Maturity Calculator
Estimate bond yield to maturity from price, face value, coupon rate, years to maturity, and payment frequency. See nominal YTM, periodic yield, and current yield.
Open toolFinance Charge Calculator
Estimate a finance charge from purchase balance, APR, and billing-cycle length using a simple daily periodic rate based on a 365-day year.
Open toolCash Back Calculator
Estimate cash back from your spending and reward rates. Enter one or more spending categories to see total cash back, your blended reward rate, and an annualized estimate.
Open toolRevenue Calculator
Calculate revenue from units sold and price per unit, or reverse the math to estimate required units or price for a revenue target.
Open toolARV Calculator
Estimate after repair value from three comparable sale prices and repair-based dollar adjustments. Average adjusted comps to get a quick ARV estimate.
Open toolBody Shape Calculator
Use this body shape calculator to compare bust, waist, and hip measurements and sort them into broad body-shape categories with a simple ruleset.
Open toolFace Shape Calculator
Use this face shape calculator to compare forehead, cheekbone, jawline, and face-length measurements and estimate your face shape.
Open toolLDL Calculator
Estimate LDL cholesterol from total cholesterol, HDL, and triglycerides with the Friedewald equation in mg/dL. Includes assumptions, common limits, examples, and a medical disclaimer.
Open toolWeight Loss Percentage Calculator
Use this weight loss percentage calculator to compare starting and current weight, then see pounds or kilograms lost and the percent change.
Open toolNavy Body Fat Calculator
Use this Navy body fat calculator to estimate body fat percentage from height, neck, waist, and hip measurements with sex-specific inputs in centimeters or inches.
Open toolMean Arterial Pressure Calculator
Use this mean arterial pressure calculator to estimate MAP from systolic and diastolic blood pressure with the standard resting approximation.
Open toolBRI Calculator
Use this BRI calculator to estimate body roundness index from waist and height, compare the result with broad adult screening bands, and review the assumptions behind the score.
Open toolFFMI Calculator
Use this FFMI calculator to estimate lean mass, fat-free mass index, and normalized FFMI from weight, height, and body fat percentage.
Open toolCFM Calculator
Estimate room airflow in CFM from length, width, ceiling height, and air changes per hour. Works in feet or meters and shows room volume in ft3 and m3.
Open toolElevation Grade Calculator
Convert rise and run into percent grade, slope ratio, and angle for site work and driveways. A 2-foot rise over 40 feet is a 5% grade.
Open toolSquare Yards Calculator
Calculate square yards from length and width in yards, then see the same area in square feet for turf, flooring, and material planning.
Open toolAsphalt Calculator
Estimate tons of asphalt from square footage, thickness, and asphalt density. Uses 145 lb/ft3 as a common planning default for driveway and paving jobs.
Open toolOunces to Grams Converter
Convert ounces to grams and grams to ounces with the exact avoirdupois factor. 1 oz equals 28.349523125 g, so 8 oz is 226.8 g and 16 oz is 453.59237 g.
Open toolCents to Dollars Converter
Convert cents to dollars and dollars to cents with exact cent math. 375 cents is $3.75 and $18.40 is 1,840 cents. Includes penny roll context.
Open toolInch-Pounds to Foot-Pounds Converter
Convert inch-pounds to foot-pounds and back for torque specs. 180 in-lb is 15 ft-lb because 12 in-lb equals 1 ft-lb.
Open toolNm to in-lbs Converter
Convert newton-meters to inch-pounds and back with clear torque formulas, worked examples, and quick checks for low-torque fasteners.
Open toolReal Estate Commission Calculator
Calculate real estate commission from a home sale price and rate. See the total commission, the listing and buyer agent split, and each broker's cut.
Open toolPrice Elasticity Calculator
Calculate price elasticity of demand with the midpoint method from an old and new price and quantity, and see if demand is elastic, inelastic, or unit elastic.
Open toolWACC Calculator
Calculate weighted average cost of capital (WACC) from the market value of equity, market value of debt, cost of equity, cost of debt, and tax rate.
Open toolMarginal Cost Calculator
Calculate marginal cost from the change in total cost divided by the change in quantity produced. Enter old and new total cost with old and new output.
Open toolPVIFA Calculator
Calculate the present value interest factor of annuity (PVIFA) from a periodic rate and number of periods. See the factor and the present value of a fixed payment.
Open toolNet to Gross Calculator
Use this net to gross calculator to convert a target net (take-home) amount into the gross pay you need before taxes and deductions, using your effective deduction rate.
Open toolINR Calculator
Estimate INR from patient prothrombin time, control PT, and reagent ISI with the WHO INR formula. Includes assumptions, common limits, examples, and a medical disclaimer.
Open toolACR Calculator
Calculate the urine albumin-to-creatinine ratio (ACR / UACR) in mg/g from urine albumin and urine creatinine. Choose mg/dL, mg/L, or g/L units and see published interpretation bands with a medical disclaimer.
Open toolCholesterol Units Converter
Convert total, LDL, or HDL cholesterol between mg/dL and mmol/L with the cholesterol factor of 38.67. Includes a lab lookup table and a glucose warning.
Open toolGestational Age Calculator
Estimate gestational age from your last menstrual period. See weeks and days, trimester, percent complete, and the estimated due date from one date check.
Open toolBlood Type Calculator
Enter both parents' ABO type and Rh factor to see every blood type their child could inherit, based on standard Mendelian genetics.
Open toolLean Body Mass Calculator
Use this lean body mass calculator to estimate lean mass and fat mass from weight and height with the sex-specific Boer formula.
Open toolWinning Percentage Calculator
Use this winning percentage calculator to turn any wins, losses, and ties record into a standings-style percentage, the way sports leagues rank teams.
Open toolBatting Average Calculator
Calculate batting average from hits and at-bats. Enter your stats to get AVG in the traditional .300 format, plus the decimal value and outs.
Open toolStride Length Calculator
Estimate your walking or running stride length from your height using standard gender-based multipliers. See stride length in inches and centimeters plus steps per mile.
Open toolBike Size Calculator
Use this bike size calculator to find a recommended frame size range from your height for road, mountain, and hybrid bikes, plus a height band reference table.
Open toolBeam Deflection Calculator
Calculate beam deflection for a simply supported beam under a center point load. Enter load, span length, modulus of elasticity, and moment of inertia.
Open toolRafter Length Calculator
Calculate common rafter length from horizontal run and roof pitch per 12. Add an eave overhang and get the result in inches, feet, and feet and inches.
Open toolRetaining Wall Calculator
Estimate how many retaining wall blocks you need from wall length, height, and block size. Includes a buried base course, cap row, and waste factor for accurate ordering.
Open toolConcrete Block Calculator
Estimate how many standard 8x8x16 concrete blocks you need for a wall from its length and height. Adds a waste factor and an optional cost per block so you can order with confidence.
Open toolDays to Months Converter
Convert days to months and months to days using the average of 30.44 days per month. See a months-and-days breakdown for values like 45 and 90 days.
Open toolMinutes to Seconds Converter
Convert minutes to seconds and seconds back to minutes. 1 minute is exactly 60 seconds, so 5 minutes is 300 seconds and 90 seconds is 1.5 minutes.
Open toolMetric to Inches Converter
Convert millimeters, centimeters, or meters to inches and back. 1 inch is exactly 25.4 mm, so 1 meter is about 39.37 inches.
Open toolNickels to Dollars Converter
Convert nickels to dollars and dollars to nickels. 20 nickels equals $1, so 87 nickels is $4.35 and $5 is 100 nickels. Includes nickel roll counts.
Open toolMinecraft Circle Generator
Generate pixel-perfect circle and sphere blueprints for Minecraft builds. Pick any diameter up to 256 and get a block-by-block layout grid.
Open toolTrigonometry Calculator
Calculate sin, cos, tan, and right-triangle sides from an angle. Enter an angle and pick a known side to get all six trig ratios and the other two sides.
Open toolArc Length Calculator
Calculate arc length and sector area from radius and central angle. Enter the angle in degrees or radians and get the arc length, sector area, and circumference.
Open toolWatt Calculator
Calculate power in watts from voltage, current, and resistance using Ohm's law. Enter any two values and get watts, amps, volts, and ohms.
Open toolMonth Counter
Count the months between two dates and get a years-and-months breakdown. Enter a start and end date to find exactly how many months apart they are.
Open toolWet Bulb Calculator
Estimate wet-bulb temperature, dew point, and heat stress risk from air temperature and relative humidity. Understand when outdoor conditions become dangerous.
Open toolRectangle Calculator
Calculate the area, perimeter, and diagonal of a rectangle from length and width. Free rectangle calculator with step-by-step formulas and a quick reference table.
Open toolDay of the Year
Find the day number for any date, plus days left in the year and the percent of the year completed, with leap-year support.
Open toolWalking Calorie Calculator
Find out how many calories walking burns. A 155 lb person walking 30 minutes at 3 mph burns about 129 calories. Uses standard MET values by walking speed.
Open toolCircumference to Diameter Calculator
Convert circumference to diameter by dividing by pi. A circle with a circumference of 31.4 has a diameter of about 10. Works in both directions and shows the radius.
Open toolNRR Calculator (Net Run Rate)
Calculate cricket net run rate. A team scoring 287 in 50 overs and conceding 243 in 50 has an NRR of +0.880. Handles partial overs the ICC way.
Open toolBirthday Calculator
Find the day of the week you were born, count the days until your next birthday, and see what age you are turning. Handles leap year birthdays too.
Open toolPercentage Change Calculator
Calculate percentage change between two numbers. Going from 40 to 50 is a 25% increase, while 50 to 40 is a 20% decrease. See the formula and worked examples.
Open toolPercentage Difference Calculator
Calculate the percentage difference between two numbers. Comparing 40 and 60 gives a 40% difference, measured against their average. Order does not matter.
Open toolPuppy Weight Calculator
Estimate your puppy's adult weight from its current weight and age. A 12 lb puppy at 16 weeks projects to about 39 lb full grown. Uses the growth-rate rule.
Open toolLog Base 2 Calculator
Calculate log base 2 of any positive number. Log2 of 8 is 3 because 2 to the power 3 equals 8. Also shows log base 10 and the natural log.
Open toolGrams to Cups Converter
Convert grams to cups for flour, sugar, butter, and more. 90 grams of flour is 0.72 cups, while 90 grams of sugar is only 0.45 cups. Density matters.
Open toolHours Until Calculator
Count the hours and minutes until any time. From 9:00 AM to 5:30 PM is 8 hours 30 minutes. Works for later today, tomorrow, or a specific date.
Open toolInverse Tangent Calculator (Arctan)
Calculate tan inverse (arctan) of any number. Arctan of 1 is 45 degrees, arctan of 0.5 is about 26.57 degrees. Results in degrees and radians.
Open toolRemainder Calculator
Find the remainder and quotient of any division. 23 divided by 5 is 4 remainder 3, since 5 x 4 + 3 = 23. Handles negative numbers the standard math way.
Open toolP-Value Calculator
Convert a z-score to a p-value. A z-score of 1.96 gives a two-tailed p-value of 0.05, the classic significance threshold. Two-tailed and one-tailed tests.
Open toolFuel Consumption Calculator
Convert MPG to L/100km and L/100km to MPG instantly. A trip of 650 km on 45 liters is 6.92 L/100 km, about 34 MPG. Handles US and UK MPG plus km/L.
Open toolTriangle Area Calculator
Find the area of a triangle from base and height, three sides (Heron's formula), or two sides and an angle. A triangle with base 10 and height 6 has area 30.
Open toolPercentage Decrease Calculator
Calculate percentage decrease between two values. A price falling from $80 to $60 is a 25% decrease. Shows the formula, the raw difference, and worked examples.
Open toolSwimming Calorie Calculator
Find out how many calories swimming burns. A 155 lb person swimming freestyle for 30 minutes burns about 214 calories, and butterfly nearly doubles that.
Open toolDesk Height Calculator
Find your ideal desk and chair height from your body height. A 5'9" (175 cm) person needs a sitting desk around 73.5 cm and a standing desk around 108.5 cm.
Open toolAntilog Calculator
Calculate the antilog of any number. The antilog of 3 in base 10 is 1000, because 10 to the power 3 equals 1000. Works with base 10, base e, or any base.
Open toolAverage Percentage Calculator
Average multiple percentages correctly. Test scores of 72%, 85%, and 90% average to 82.33%. Supports weighted averages when the groups differ in size.
Open toolAge Difference Calculator
Calculate the exact age gap between two people from their birth dates. Someone born March 1995 and someone born August 1998 are 3 years 5 months apart.
Open toolStrike Rate Calculator (Cricket)
Calculate cricket strike rate. A batter scoring 45 runs off 32 balls has a strike rate of 140.63. Covers batting (runs per 100 balls) and bowling strike rates.
Open toolHemisphere Volume Calculator
Find the volume of a hemisphere with V = (2/3) pi r cubed. A hemisphere with radius 6 has a volume of about 452.4. Also computes surface areas.
Open toolSector Area Calculator
Find the area of a circle sector from radius and central angle. A 90 degree sector of a radius 8 circle has an area of 50.27, a quarter of the full circle.
Open toolCone Volume Calculator
Find the volume of a cone with V = (1/3) pi r squared h. A cone with radius 4 and height 9 has a volume of about 150.8. Also computes slant height and surface area.
Open toolDog Pregnancy Calculator
Estimate your dog's due date from the mating date. Canine pregnancy lasts about 63 days, with most litters arriving between day 58 and day 68.
Open toolGematria Calculator
Calculate the gematria value of any word or name. In English ordinal gematria, LOVE equals 54 (L=12, O=15, V=22, E=5). Shows ordinal, reduced, and Sumerian values.
Open toolExpiration Date Calculator
Calculate when something expires from its production date and shelf life. A product made March 15 with an 18-month shelf life expires September 15 the next year.
Open toolHex to Text Converter
Convert hexadecimal to readable text and back. The hex bytes 48 65 6c 6c 6f decode to the word Hello. Handles spaces, 0x prefixes, and full UTF-8.
Open toolSphere Volume Calculator
Find the volume of a sphere from its radius, then check the matching surface area and diameter with clear formulas, worked examples, and a quick radius table.
Open toolDice Average Calculator
Find the average roll of any dice combination. 2d6 averages 7, and 13d8 averages 58.5. Works for any count, any sides, and flat modifiers.
Open toolSemicircle Area Calculator
Find the area of a semicircle with A = pi r squared / 2. A semicircle with radius 5 has an area of 39.27 and a perimeter of 25.71 including the flat edge.
Open toolSunscreen Calculator
Estimate how long sunscreen protects your skin. Fair skin that burns in 15 minutes gets a theoretical 7.5 hours from SPF 30, but reapplication every 2 hours still rules.
Open toolRoulette Payout Calculator
Calculate roulette payouts and odds for every bet type. A $10 straight bet pays $350 at 35 to 1, with a 2.7% chance on a European wheel. Compare house edges.
Open toolAquarium Volume Calculator
Calculate aquarium volume from tank dimensions. A 36 x 18 x 16 inch tank holds about 44.9 US gallons and its water alone weighs about 374 lb.
Open toolDress Size Calculator
Find your dress size from bust, waist, and hip measurements. A 34.5-26.5-36.5 inch figure is a US 6, UK 10, EU 38. Based on the standard misses chart.
Open toolPower to Weight Ratio Calculator
Calculate power-to-weight ratio for cycling and cars. A 70 kg cyclist holding 280 watts rides at 4.0 W/kg, solid amateur racing form. Cars get hp per tonne.
Open toolGrams to Tablespoons Converter
Convert grams to tablespoons by ingredient. 40 grams of butter is 2.8 tbsp, while 40 grams of flour is 5.1 tbsp. Density makes the difference.
Open toolGrams to Teaspoons Converter
Convert grams to teaspoons by ingredient. 3 grams of salt is half a teaspoon, while 3 grams of flour is 1.15 teaspoons. Includes sugar, yeast, and more.
Open toolLetters to Numbers Converter
Convert letters to numbers with the A1Z26 cipher, where A=1 and Z=26. The word CAB becomes 3 1 2, and 8 9 decodes back to HI. Works in both directions.
Open toolCups to Pounds Converter
Convert cups to pounds by ingredient. 2 cups of flour is 0.55 lb, while 2 cups of sugar is 0.88 lb. Works in both directions with real densities.
Open toolDilution Ratio Calculator
Work out how much concentrate and water a dilution ratio needs. A 1:10 ratio in a 32 oz bottle takes 2.9 oz of concentrate and 29.1 oz of water.
Open tooleDPI Calculator
Calculate your eDPI by multiplying mouse DPI by in-game sensitivity. 800 DPI at 0.35 sens is 280 eDPI, a typical pro Valorant setting. Compare across setups.
Open tool45 45 90 Triangle Calculator
Solve a 45 45 90 triangle from one side. With legs of 5, the hypotenuse is 5 times sqrt 2, about 7.07. Get all sides, area, and perimeter instantly.
Open toolProbability Calculator
Calculate probability from favorable and total outcomes. Drawing an ace from a deck is 4 in 52, a 7.69% chance with odds of 1 to 12. Includes repeated trials.
Open toolCoin Flip Probability Calculator
Calculate the probability of getting heads in coin flips. Exactly 5 heads in 10 flips has a 24.61% chance, while at least 5 heads is 62.3%. Binomial math.
Open toolTrapezoid Area Calculator
Calculate the area of a trapezoid from its two parallel bases and perpendicular height. Includes the median length, worked examples, and clear formula notes.
Open toolAudiobook Speed Calculator
See how long an audiobook takes at faster playback. A 12-hour book at 1.5x speed finishes in 8 hours, saving 4 hours. Works for podcasts and lectures too.
Open toolGear Ratio Calculator
Calculate gear ratio from tooth counts. A 20-tooth gear driving a 60-tooth gear gives a 3:1 ratio, cutting speed to a third and tripling torque.
Open toolJump Rope Calorie Calculator
Find out how many calories jumping rope burns. A 155 lb person skipping at a moderate pace for 15 minutes burns about 218 calories, on par with running.
Open toolCritical Value Calculator
Find the z or t critical value for any confidence level, one-tailed or two-tailed test, and degrees of freedom. Instant results with worked examples.
Open toolJeans Size Calculator
Find your jeans size from a waist measurement. A 27 inch waist matches US 6 (EU 38, UK 10) for women, or 32x32 for men. Covers women's and men's denim charts.
Open toolAcreage Calculator
Convert a rectangular lot's length and width into acres, or convert acres into square feet, square yards, square meters, and hectares. Free acreage calculator.
Open toolBiking Calorie Calculator
Find out how many calories cycling burns. A 155 lb rider at 12-13.9 mph for 30 minutes burns about 295 calories. Uses standard MET values by speed.
Open toolHexagon Calculator
Calculate the area, perimeter, apothem, circumradius, and diagonal lengths of a regular hexagon from a single side length. Free hexagon calculator with formulas.
Open toolExponential Growth Calculator
Calculate exponential growth or decay from a starting value, rate, and time. Get the final value, doubling or halving time, and both discrete and continuous compounding.
Open toolDays to Weeks Converter
Convert days to weeks or weeks to days instantly. See decimal weeks and a whole-weeks-plus-remainder-days breakdown, plus total hours.
Open toolSquare Diagonal Calculator
Calculate the diagonal of a square from its side length, or the side length from a diagonal. Free calculator with area, perimeter, and step-by-step formulas.
Open toolRice Calculator
Convert uncooked rice to cooked rice, or cooked rice back to uncooked, in cups or grams. Free rice calculator using the standard tripling and 2.5x weight ratios.
Open toolRunning Calorie Calculator
Find out how many calories running burns. A 155 lb runner at 6 mph for 30 minutes burns about 362 calories. Uses standard MET values by running speed.
Open toolVertex Form Calculator
Convert y = ax^2 + bx + c into vertex form and find a parabola's vertex, axis of symmetry, and direction. Enter a, b, and c to get the turning point instantly.
Open toolMultiplication Calculator
Multiply two numbers to get the product, plus a step-by-step partial-products breakdown for whole-number factors.
Open toolUnit Price Calculator
Compare products by price per item, ounce, pound, or package. Enter cost, package count, and units per package to find the true unit price.
Open toolSignificant Figures Calculator
Count and round significant figures in decimal or scientific notation. Keep written zeros, choose 1 to 15 sig figs, and see the rounded result.
Open toolEquilateral Triangle Calculator
Find the area, height, perimeter, inradius, and circumradius of an equilateral triangle from one side length with exact standard formulas.
Open toolTrapezoidal Prism Volume Calculator
Calculate trapezoidal prism volume from two parallel bases, the perpendicular trapezoid height, and prism length. See base area and the full method.
Open toolCross-Sectional Area Calculator
Calculate the cross-sectional area of a solid round bar or hollow pipe from outer and inner diameters, including wall thickness and component areas.
Open toolPyramid Volume Calculator
Find rectangular pyramid volume from base length, base width, and perpendicular height. See base area, formula steps, examples, and unit guidance.
Open toolGrams to Fluid Ounces Converter
Convert grams to US fluid ounces using material density. See the intermediate milliliters, water example, formula, and mass-versus-volume guidance.
Open toolQuarts to Pounds Converter
Convert US liquid quarts to pounds using material density. Check water, oil, and ingredient estimates with grams and the density used.
Open toolWeightlifting Calorie Calculator
Estimate calories burned lifting weights from body weight, active minutes, and training intensity. Compare light, moderate, and vigorous MET levels.
Open toolCross Multiplication Calculator
Solve a proportion in the form a/b = c/x with cross multiplication. See the missing value, equal cross products, formula, and worked examples.
Open toolkPa to PSI Converter
Convert kilopascals to pounds per square inch or psi back to kPa. Uses 1 kPa = 0.14503773773 psi with practical pressure examples.
Open toolmL to µL Converter
Convert milliliters to microliters or µL back to mL. Uses the exact metric relationship 1 mL = 1,000 µL with decimal examples.
Open toolBaby Age Calculator
Find out exactly how old your baby is in weeks and days, months, and years. Enter a birth date and an as-of date for a calendar-accurate age breakdown.
Open toolDrive Time Calculator
Use this drive time calculator to estimate trip duration from distance and average speed, add rest stops, and find your arrival time.
Open toolGolden Ratio Calculator
Split any length into two segments using the golden ratio (phi, approximately 1.618). Enter a total and get the longer segment, shorter segment, and ratio check.
Open toolInches to cm Converter
Convert inches to centimeters and back. 1 inch is exactly 2.54 cm, so 12 inches is 30.48 cm. Enter a value and pick a direction for an instant result.
Open toolKD Ratio Calculator
Calculate your KD ratio and KDA ratio from kills, deaths, and assists. See both stats instantly with the standard zero-death display rule used in game UIs.
Open toolNether Portal Calculator
Convert Minecraft coordinates between the Overworld and the Nether using the exact 1 to 8 scale ratio. Enter X and Z to find where to build your linked portal.
Open toolPPM to mg/L Converter
Convert ppm to mg/L and mg/L to ppm for water quality readings. Uses the standard 1:1 dilute water assumption, with an optional density input for other solutions.
Open toolTV Mounting Height Calculator
Find the right TV mounting height for your wall using screen size and seated eye level. Get the bracket bottom, center, and top height in inches.
Open toolWeeks to Months Converter
Convert weeks to months instantly. See total days, a decimal-months figure, and a whole-months-plus-remainder-days breakdown in one result.
Open toolCartesian to Polar Calculator
Convert Cartesian (x, y) coordinates to polar (r, theta) and back. Get the radius, the angle in degrees and radians, and the quadrant, all rounded for quick checks.
Open toolAngular Velocity Calculator
Calculate angular velocity (omega) in rad/s from an angle and time, from linear speed and radius, or from rpm. Get instant conversions to rpm, degrees per second, and rotation period.
Open toolBSA Calculator (Body Surface Area)
Calculate body surface area in square meters with the Mosteller and Du Bois formulas. Enter height and weight in metric or US units and see both BSA estimates instantly.
Open toolConcentration Calculator (Molarity)
Calculate solution molarity in mol/L from moles and volume, or from mass, molar mass, and volume. Get the concentration, moles of solute, and mmol/L instantly.
Open toolEngine Displacement Calculator
Calculate total engine displacement from bore, stroke, and cylinder count. Get results in cc, liters, and cubic inches with per-cylinder swept volume.
Open toolHypotenuse Calculator
Find the hypotenuse of a right triangle from two legs, or solve for a missing leg from the hypotenuse and one side. Uses the Pythagorean theorem c = sqrt(a squared plus b squared).
Open toolMole Calculator
Convert between moles, mass in grams, and molar mass with one tool. Solve for any of the three values and see the number of particles using Avogadro's number.
Open toolParallel Resistor Calculator
Find the total resistance of resistors in parallel or in series. Enter up to four values, pick a wiring mode, and get the equivalent resistance in ohms instantly.
Open toolPool Salt Calculator
Find out how much salt to add to a saltwater pool. Enter your pool volume in gallons, your current salinity, and your target ppm to get pounds of salt, 40-lb bags, and kilograms.
Open toolPythagorean Theorem Calculator
Solve a right triangle with the Pythagorean theorem. Find the hypotenuse from two legs, or find a missing leg from the hypotenuse and one leg, plus area and perimeter.
Open toolRelative Humidity Calculator
Calculate relative humidity from air temperature and dew point, or work backward from humidity to find the dew point. Uses the Magnus approximation for fast, accurate estimates in Celsius.
Open toolSolar Panel Calculator
Find out how many solar panels you need from your monthly electricity use. This solar panel calculator estimates system size in kilowatts, panel count, and yearly production.
Open toolT-Statistic Calculator
Calculate the one-sample t statistic from a sample mean, population mean, sample standard deviation, and sample size. See the t score, degrees of freedom, and standard error instantly.
Open toolTorque Calculator
Calculate torque from force, lever arm, and angle using tau = F times r times sin(theta). Get results in newton-meters and pound-feet with the effective lever arm shown.
Open toolVelocity Calculator
Calculate velocity two ways. Find average velocity from displacement and time, or final velocity from initial velocity, acceleration, and time. See results in m/s, km/h, and mph.
Open toolWavelength Calculator
Calculate wavelength from frequency and wave speed, or find frequency from wavelength. Supports light, sound, and custom waves with instant results in meters, nanometers, and hertz.
Open toolPrime Number Checker
Check whether any whole number is prime. Enter a number and see the verdict, its smallest factor, the full prime factorization, and the nearest primes above and below it.
Open toolInch to Meter Converter
Convert inches to meters and meters to inches with the exact factor of 0.0254 meters per inch. See fast answers for 12, 36, and 100 inches and full decimal precision.
Open toolmL to Tablespoons Converter
Convert milliliters to US tablespoons and tablespoons to mL using the exact 14.7867648 mL per tablespoon rate. See common values like 15 mL, 30 mL, and 60 mL.
Open toolDimes to Dollars Converter
Convert dimes to dollars and dollars to dimes with the exact 10 dimes per dollar rule. See how much 25, 50, or 100 dimes are worth and how many dimes fill a dollar.
Open toolDays to Years Converter
Convert days to years and years to days using the average 365.25 days per year. See decimal years and a years-and-days breakdown for values like 1000 and 3650 days.
Open toolSurface Area Calculator
Find the surface area of a cube, cuboid, sphere, cylinder, or cone. A cube with 3 inch sides has a surface area of 54 square inches. Pick a shape and enter its dimensions.
Open toolAcceleration Calculator
Calculate acceleration from initial velocity, final velocity, and time. Get results in m/s squared plus distance traveled and g-force. Free, no signup.
Open toolTime From Now Calculator
Find what time it will be in any number of hours and minutes from now. Get the exact time, date, and day of the week. Free, no signup.
Open toolPercent Yield Calculator
Calculate percent yield from actual and theoretical yield, or solve for any missing value. Get instant results for chemistry lab work.
Open toolCat Age Calculator
Convert your cat's age to human years. Enter your cat's age to see the human-age equivalent and life stage. Free, no signup.
Open toolmcg to mL Converter
Convert micrograms (mcg) to milliliters (mL) using the concentration. Enter the dose and strength to get the volume. Works in both directions.
Open toolHP to Amps Converter
Convert motor horsepower to amps for single-phase and three-phase circuits. Enter HP, voltage, power factor, and efficiency to get full-load current.
Open toolWatt-Hours Calculator
Calculate watt-hours from watts and hours, or solve for power or time. Convert to kilowatt-hours. Free energy calculator for batteries and appliances.
Open toolSpecific Heat Calculator
Calculate heat energy, mass, specific heat capacity, or temperature change using Q = mc delta T. Solve for any missing value with worked examples.
Open toolAnniversary Calculator
Find how many years since a date and the days until the next anniversary. Enter a start date and get years completed, days since the last anniversary, and days until the next one.
Open toolBillion to Trillion Converter
Convert billion to trillion and trillion to billion instantly. 500 billion is 0.5 trillion, and 3.2 trillion is 3,200 billion. See the full number to verify the conversion.
Open toolmg to Teaspoon Converter
Convert milligrams to teaspoons by ingredient. 3,000 mg of salt is half a teaspoon, but 3,000 mg of flour is over a full teaspoon. Includes salt, sugar, baking powder, baking soda, and flour.
Open toolDay Counter
Count the days since a past date or the days until a future date. Pick any calendar date and instantly see how many days have passed or how many days are left.
Open toolLiters to Pounds Converter
Convert liters to pounds and pounds to liters by substance. 1 liter of water weighs 2.2 lbs, 1 liter of milk is 2.27 lbs, and 1 liter of oil is 2.03 lbs. Includes a custom density option.
Open toolmL to tsp Converter
Convert milliliters to US teaspoons and teaspoons to mL using the exact 4.92892159375 mL per teaspoon rate. See common values like 5 mL, 15 mL, and 30 mL.
Open toolTriangle Height Calculator
Find the height, base, or area of a triangle using the formula area = 1/2 x base x height. Enter any two values and get the third instantly.
Open toolMicrowave Wattage Converter
Convert microwave cooking times between different wattages. A 5-minute recipe at 1100W needs about 7 min 51 sec at 700W.
Open toolGallons to kg Converter
Convert gallons to kilograms and kg to gallons using density. 1 gallon of water is 3.785 kg, 1 gallon of milk is 3.899 kg. Includes water, milk, gasoline, and honey presets.
Open toolPints to Cups Converter
Convert pints to cups and cups to pints instantly. 1 pint equals 2 cups, 3 pints equals 6 cups, and 8 cups equals 4 pints. Free pints to cups converter.
Open toolCalories Burned Standing Calculator
Estimate how many calories you burn while standing. A 70 kg person standing for 8 hours burns about 1,008 calories using the standard MET value of 1.8.
Open toolTriangular Prism Volume Calculator
Calculate the volume of a triangular prism from base edge, triangle height, and prism length. Volume = 1/2 x base edge x triangle height x prism length.
Open toolDensity Calculator
Calculate density, mass, or volume from any two known values using the formula density = mass / volume. Enter mass and volume to find density, or any two of the three.
Open toolTaco Bar Calculator
Plan a taco bar for any group size. Calculate how much meat, toppings, and shells you need. 10 guests at 3 tacos each with 2 oz meat per taco needs about 3.75 lbs of meat.
Open toolNet Ionic Equation Calculator
Find the net ionic equation for common precipitation reactions. Select two aqueous compounds and see the molecular, total ionic, and net ionic equation with spectator ions.
Open toolD&D 5e Point Buy Calculator
Calculate point buy totals for Dungeons & Dragons 5th Edition ability scores. Standard 27-point budget with scores from 8 to 15. See the cost breakdown for each ability.
Open toolmm to Foot Converter
Convert millimeters to feet and feet to millimeters using the exact 304.8 mm per foot rate. 1000 mm is about 3.28 feet. 5 feet is exactly 1,524 mm.
Open tool8 Hour Shift Calculator
Calculate when an 8-hour shift ends including breaks. Enter a start time and break length to get the end time. Or enter clock-in and clock-out to calculate hours worked.
Open toolFlow Rate Calculator
Calculate flow rate, volume, or time from any two known values. Flow rate = volume / time. Enter volume and time to find the rate, or any two of the three values.
Open toolDosage Calculator
Estimate pediatric medication dosages using Clark's, Young's, Fried's, and weight-based formulas. This is a reference tool only and not a substitute for professional medical advice.
Open toolOctagon Calculator
Calculate the area, perimeter, apothem, and circumradius of a regular octagon from its side length. Area ≈ 4.828 × side² for a regular octagon.
Open toolMonths Between Dates Calculator
Calculate the number of months between two dates. Includes a years-and-months breakdown and total weeks. Enter a start and end date to get calendar months between them.
Open toolDegrees of Freedom Calculator
Calculate degrees of freedom for a one-sample t test, two-sample t test, Welch's t test, chi-square test, or one-way ANOVA. Pick a test type and get an instant df.
Open toolDice Probability Calculator
Find the odds of rolling a specific dice total. 2d6 exactly 7 hits 16.67% of the time. Works for any dice count, sides, and exactly, at-least, or at-most target.
Open toolLeap Year Calculator
Check if a year is a leap year using the Gregorian rule, see how many days it has, and find the nearest leap years before and after it.
Open toolWords Per Minute Calculator
Find your words per minute rate, or the time a script or speech will take at a target WPM. Works for reading, speaking, and typing paces.
Open toolPerimeter Calculator
Calculate the perimeter of a square, rectangle, triangle, circle, or regular polygon. Pick a shape, enter the side lengths, and get the exact perimeter with a formula breakdown.
Open toolPie Chart Calculator
Turn category values into pie chart slices. Enter values like 30, 45, 25 and get each slice's percentage and exact angle in degrees.
Open toolMB to GB Converter
Convert MB to GB or GB to MB instantly with decimal (1000) and binary (1024) storage standards, matching vendor labels or OS file sizes.
Open toolTransferrin Saturation Calculator
Calculate transferrin saturation (TSAT) from serum iron and total iron-binding capacity (TIBC). Enter both values in mcg/dL and see general educational reference bands with a medical disclaimer.
Open toolTriangular Pyramid Volume Calculator
Find the volume of a tetrahedron from a triangular base and height, or from one edge of a regular tetrahedron. Two modes, worked examples, formulas.
Open toolTaper Calculator
Enter a large diameter, small diameter, and length to get taper per foot, taper ratio, and included and half angle in degrees.
Open toolBattery Charge Time Calculator
Estimate how long a battery takes to charge from your capacity, current and target percentage, charger current, and real-world charging efficiency.
Open toolSquare Feet to Cubic Yards Calculator
Convert square footage and fill depth into cubic yards for concrete, gravel, soil, sand, or mulch. Enter depth in inches or feet and get an instant volume.
Open toolKt/V Calculator
Calculate single-pool Kt/V for hemodialysis adequacy using the Daugirdas second-generation equation from pre- and post-dialysis BUN, session length, ultrafiltration volume, and post-dialysis weight.
Open toolDimensional Weight Calculator
Calculate carrier dimensional weight from box dimensions, compare it to actual weight, and find your billable shipping weight in pounds or kilograms.
Open toolEU/US/UK Shoe Size Converter
Convert shoe sizes between US, EU, UK, and cm. A men's US 9 is EU 42, UK 8, 27 cm. A women's US 8 is EU 39, UK 6, 25 cm. Covers half sizes 5-13 men, 5-11 women.
Open toolDrops to mL Converter
Convert drops to mL and mL to drops using the standard 20 drops per mL rate, or adjust for essential oils, tinctures, and eye drops. 10 drops equals 0.5 mL at the standard rate.
Open toolCircle Skirt Calculator
Enter your waist and skirt length to get the exact pattern radius for a full, half, or quarter circle skirt, plus an estimated fabric yardage.
Open toolInverse Cosine Calculator (Arccos)
Calculate cos inverse (arccos) of a ratio between -1 and 1. Arccos of 0.5 is 60 degrees, arccos of 0 is 90 degrees. Results in degrees and radians.
Open toolHair Growth Calculator
Estimate how long your hair will grow or how many months until it reaches a goal length. Uses the average growth rate of 0.5 inch per month. Free, no signup.
Open toolGold Weight Calculator
Convert gold weight between grams, troy ounces, pennyweight, kilograms, and tola, then estimate melt value from karat purity and your own gold price.
Open toolPercent to Goal Calculator
Calculate percent of goal reached from a current value and a target. Raising $3,750 toward $5,000 is 75%, with $1,250 left.
Open toolKg to Gallons Converter
Convert kilograms to US gallons and gallons to kg using liquid density. 1 US gallon of water weighs about 3.79 kg, gasoline is closer to 2.8 kg.
Open toolWater Tank Volume Calculator
Calculate water tank volume for rectangular, vertical cylindrical, and horizontal cylindrical tanks. Get total capacity in US gallons, liters, and cubic feet.
Open toolMinute Calculator
Add or subtract minutes from any start time to get the exact result. Adding 90 minutes to 11:30 PM lands at 1:00 AM the next day.
Open toolPPM Calculator
Convert a concentration between ppm, percent, ppb, and a 1-in-N ratio. 5,000 ppm is 0.5%, 5,000,000 ppb, and 1 in 200.
Open toolSum of Series Calculator
Calculate the sum of an arithmetic or geometric series. Enter the first term, number of terms, and common difference or ratio for an instant total.
Open toolKorean Age Calculator
Convert a birth date to Korean age, international age, and counting age. Someone born December 31 turns 2 in Korean age the very next day.
Open toolGraduation Year Calculator
Enter a birthdate and see the expected high school and college graduation year, based on standard US kindergarten cutoff rules and a 12-year K-12 track.
Open toolGreater Than Less Than Calculator
Compare two numbers instantly and see whether the first is greater than, less than, or equal to the second, with the correct symbol shown.
Open toolDuckworth-Lewis (DLS) Calculator
Estimate a DLS-style par score and revised target for a rain-hit cricket match. Enter Team 1's score, overs available, and Team 2's overs and wickets lost.
Open toolFlag Bet Calculator
Work out Flag bet returns from 4 selections. Enter decimal odds, mark each pick won or lost, and see all 23 bets settled, including doubles, trebles, the fourfold, and every SSA leg.
Open toolQuarts to Gallons Converter
Convert US quarts to gallons and gallons to quarts. 1 gallon equals 4 quarts, so 3 gallons is 12 quarts and 6 quarts is 1.5 gallons. Includes cup and pint equivalents.
Open toolMM to M Converter
Convert millimeters to meters and meters to millimeters. 1 meter equals 1000 mm, so 2500 mm is 2.5 m and 3 m is 3000 mm. Includes centimeter and kilometer equivalents.
Open toolKnots to KPH Converter
Convert knots to km/h and km/h to knots. 1 knot equals 1.852 km/h, so 20 knots is 37.04 km/h. Includes miles per hour and meters per second equivalents.
Open toolD20 Dice Roller
Roll a d20 online, plus any number of dice with an optional modifier. See each roll, the sum, the total, and the average for tabletop games and math practice.
Open toolDiamond Problem Solver
Solve the algebra diamond problem in both directions. Enter two factors to get the product and sum, or enter a product and sum to find the two numbers that multiply and add to them.
Open toolT-Test Calculator
Run a one-sample, two-sample pooled, or Welch t-test from summary statistics. Get the t statistic, degrees of freedom, and two-tailed p-value with a plain-language significance note at alpha 0.05.
Open toolPlayback Speed Calculator
Find out how long a video or audio takes at 1.25x, 1.5x, or 2x speed and how much time you save. A 60 minute video at 1.5x takes 40 minutes, saving 20 minutes.
Open toolPlate Weight Calculator
Calculate the weight of a steel, stainless, aluminum, or copper plate. A 48 in x 96 in steel plate 0.25 in thick weighs about 326.7 lb. Supports inches and millimeters.
Open toolFurnace Size Calculator
Estimate the furnace size you need in BTU per hour from home square footage and climate zone. A 2000 sq ft home in a cold climate needs about 90000 to 100000 BTU.
Open toolA broad calculator hub is only useful if it helps you choose the right tool fast. The best way to use this page is to begin with the outcome you need, then move into the category built for that type of answer. A monthly payment question belongs in Finance, not in the general percentage tools. A date gap belongs in Time and Date, not in Converters. A room material estimate belongs in Construction and Home, even if measurements are involved. That structure cuts down on wrong inputs, repeated work, and false confidence from using a calculator that solves a different problem than the one you actually have.