Unit Converter
5 kilometers equals 3.106856 miles, and 150 pounds equals 68.038855 kilograms. This unit converter handles the three measurement groups people look up most often: length, weight, and temperature. Pick a conversion type, enter a value, choose the unit you already have, and choose the unit you need, and the tool returns the converted figure instantly. Length covers millimeters through miles, weight covers milligrams through pounds and ounces, and temperature covers Celsius, Fahrenheit, and Kelvin using the correct scale equations instead of a simple multiplier. It is built for the everyday moments where a recipe, a shipping label, a workout log, a travel itinerary, or a homework problem gives you a number in one unit and you need it in another, without pulling out a reference chart or doing the base-unit math by hand.
Quick answer
Select a conversion type first: length, weight, or temperature. Each group has its own set of supported units.
What this tells you
- •Select a conversion type first: length, weight, or temperature. Each group has its own set of supported units.
- •Length and weight conversions route through a shared base unit (meters for length, kilograms for weight), which keeps every unit pair consistent.
- •Temperature conversions use the actual Celsius, Fahrenheit, and Kelvin formulas because those scales are offset, not simply scaled, so a single multiply-and-divide step would not work.
- •Results are rounded to 6 decimal places for readability, while the underlying math uses full-precision standard conversion factors.
- •The tool accepts common metric and imperial units side by side, so you can move between systems in one step instead of converting twice.
How to Use
- 1Choose a conversion type: length, weight, or temperature.
- 2Enter the value you want to convert. Decimals are fine, so values like 5.5 or 0.125 work.
- 3Enter the source unit you already have, such as km, lb, or C.
- 4Enter the target unit you want to see, such as mi, kg, or F.
- 5Calculate to see the converted value along with the unit labels and the conversion used.
How It Works
Formula
Length or weight: converted value = input × (source-to-base factor) ÷ (target-to-base factor)
Temperature: convert to Celsius first, then apply the C-to-target formulaLength conversions run through meters as the base unit, and weight conversions run through kilograms. The tool multiplies your input by the source unit's factor to get a base value, then divides by the target unit's factor to get the final answer. For example, 5 km becomes 5 × 1000 = 5000 meters, and dividing by the mile factor of 1609.344 gives 3.106856 mi. Temperature cannot use this same multiply-and-divide shortcut because Celsius, Fahrenheit, and Kelvin have different zero points, not just different step sizes. The tool always converts the input to Celsius first using C = value, C = (F − 32) × 5⁄9, or C = K − 273.15, then converts that Celsius figure to the target scale using F = C × 9⁄5 + 32 or K = C + 273.15.
Calculation note: values are processed in the order shown above, using the current input units.
Worked Examples
Length conversion example
Five kilometers equal 5000 meters. Dividing 5000 by the mile factor of 1609.344 gives 3.106856 mi. This kind of conversion comes up when a race distance, road sign, or travel itinerary is listed in kilometers but you think in miles, or the other way around.
Weight conversion example
One pound equals 0.45359237 kilograms, so 150 pounds equal 150 × 0.45359237 = 68.038855 kg. This is a common check for body weight readings, luggage limits, or shipping weights when a form or scale expects kilograms instead of pounds.
Temperature conversion example
Subtract 32 from 98.6 to get 66.6, then multiply by 5⁄9 to get 37. A normal human body temperature of 98.6°F converts to exactly 37°C, which is why that pair of numbers shows up so often in health and cooking contexts alike.
Length conversion example: miles to kilometers
One mile is defined as exactly 1609.344 meters, which is 1.609344 kilometers. This fixed factor is why a 26.2-mile marathon is commonly listed as 42.195 kilometers on international race materials.
Weight conversion example: grams to ounces
Since one ounce equals 28.3495231 grams, 500 grams divided by that factor gives 17.636981 oz. Recipes and food packaging often list weight in grams internationally and ounces in the US, so this conversion comes up frequently in the kitchen.
Common Unit Conversion Reference
Frequently looked-up conversions across length, weight, and temperature.
| Category | From | To | Result |
|---|---|---|---|
| Length | 1 km | mi | 0.621371 mi |
| Length | 1 mi | km | 1.609344 km |
| Length | 1 in | cm | 2.54 cm |
| Length | 1 ft | m | 0.3048 m |
| Weight | 1 kg | lb | 2.204623 lb |
| Weight | 1 lb | kg | 0.453592 kg |
| Weight | 1 oz | g | 28.349523 g |
| Temperature | 0 C | F | 32 F |
| Temperature | 100 C | F | 212 F |
| Temperature | 37 C | F | 98.6 F |
Length and weight factors are fixed multipliers. Temperature conversions use offset formulas, so they never scale as a simple multiplication.
Common mistakes
- Applying a length factor to a weight value or vice versa. Each conversion group has its own set of supported units, and mixing them returns no result rather than a wrong one.
- Assuming temperature scales as a straight multiplier. Doubling a Celsius value and converting to Fahrenheit does not double the Fahrenheit reading, because the scales have different zero points.
- Mistyping a unit abbreviation, such as entering "kgs" instead of "kg" or "F" written as "fahrenheit." The tool matches supported abbreviations exactly, so an unrecognized label is rejected.
- Confusing mass and weight in casual language. This tool converts mass units like kilograms and pounds, which is what people mean in daily use even though "weight" and "mass" are technically different in physics.
- Rounding an intermediate result before converting again. Chaining a rounded output into a second manual conversion compounds small errors, so convert directly from the original value instead.
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