Hex Calculator
0x1F + 0x0A = 0x29, which is 41 in decimal. That is the kind of quick check this hex calculator is built for. Enter two hexadecimal values, choose add, subtract, multiply, or divide, and the tool returns both the hex result and the decimal interpretation of each input. It is useful when you are working with byte values, memory offsets, masks, color channels, packet fields, or homework problems and want a fast answer without mentally converting every step. This version stays narrow on purpose. It handles whole-number hex arithmetic, accepts values with or without a 0x prefix, and shows division as an integer quotient.
Quick answer
Hexadecimal is base 16, so each digit can be 0 through 9 or A through F, where A means 10 and F means 15.
What this tells you
- •Hexadecimal is base 16, so each digit can be 0 through 9 or A through F, where A means 10 and F means 15.
- •The calculator trims the input, removes one optional 0x prefix, and parses the remaining characters as a non-negative hex number.
- •It converts both hex inputs to decimal, performs the selected arithmetic operation, then converts the result back to uppercase hex.
- •The page shows the decimal value of A and B as well as the final result, which makes it easier to sanity-check your work when you are learning or debugging.
- •Division in this tool returns the integer quotient only. If 0x7B is divided by 0x10, the decimal math is 123 divided by 16, which becomes 7, not 7.6875.
- •Hex output is formatted as an unsigned 32-bit value, so subtraction that goes below zero can produce a large wraparound-looking hex result even though the decimal result is negative.
How to Use
- 1Enter Hex A and Hex B using digits 0 through 9 and letters A through F. You can type uppercase or lowercase.
- 2Include the 0x prefix if you like, or leave it off. Both 1f and 0x1F are accepted.
- 3Choose the operation. Add and subtract are common for offsets and counters. Multiply is useful for block sizing. Divide is useful for quick quotient checks.
- 4Click calculate and read both outputs together. The hex result answers the base-16 question, while the decimal lines let you verify that the parser read your inputs the way you expected.
- 5For division, remember that this calculator gives the whole-number quotient only. If you need the remainder, use a remainder or long-division tool instead.
- 6If a result looks strange after subtraction, check the decimal line first. A negative decimal result can still appear as a large unsigned hex value because of how this tool formats hex output.
- 7Keep the inputs plain. Spaces inside the number, commas, signs, and separators are not supported here.
How It Works
Formula
decimalA = parseInt(hexA, 16)
decimalB = parseInt(hexB, 16)
resultDecimal = operation(decimalA, decimalB)
for divide: resultDecimal = floor(decimalA / decimalB)
resultHex = 0x + unsigned32(resultDecimal).toString(16).toUpperCase()The calculator first strips one optional 0x prefix and validates that the rest of each input contains only hex digits. It then converts both values to decimal and runs the selected operation on whole numbers. Addition, subtraction, and multiplication behave the way you would expect from standard integer arithmetic. Division uses the integer quotient by applying floor to the decimal result, so any fractional part is discarded. After the decimal result is computed, the tool formats the hex output in uppercase and treats that hex display as an unsigned 32-bit value. That detail matters when the decimal answer is negative, because the decimal line and the hex line will no longer look like simple signed versions of each other.
Calculation note: values are processed in the order shown above, using the current input units.
Worked Examples
Register offset addition
0x1F is 31 in decimal and 0x0A is 10. Add them and you get 41, which is 0x29 in hex. This is a common quick-check case when you are stepping through offsets or summing byte values by hand.
Simple subtraction that stays positive
0x2C equals 44 and 0x10 equals 16. Subtracting gives 28, which converts back to 0x1C. This is the cleanest kind of subtraction to verify in the tool because both the decimal and hex outputs stay intuitive.
Block size multiplication
0x20 is 32 and 0x08 is 8. Multiplying them gives 256, which is 0x100 in hex. Results like this come up in memory sizing, page calculations, and repeated unit scaling where powers of two are common.
Integer division for page counts
0x7B is 123 decimal and 0x10 is 16 decimal. Dividing 123 by 16 gives 7.6875, but this tool keeps only the integer quotient. That is why the displayed answer is 7, or 0x7 in hex. It is useful when you only care how many full chunks fit.
Handy hex values worth recognizing on sight
These are the checkpoints people bump into all the time when reading dumps, registers, and low-level documentation.
| Hex value | Decimal value | Why it matters |
|---|---|---|
| 0x0F | 15 | Largest value that fits in one hex digit |
| 0x10 | 16 | One full base-16 carry into the next place |
| 0xFF | 255 | Maximum unsigned value in one byte |
| 0x100 | 256 | First value beyond one byte |
| 0x400 | 1024 | Common size breakpoint in memory and storage math |
| 0xFFFF | 65535 | Maximum unsigned value in two bytes |
If you can recognize 0x10, 0xFF, 0x100, and 0xFFFF without converting them from scratch every time, hex arithmetic gets much easier to reason about.
What this hex calculator assumes
This tool assumes both inputs are non-negative whole numbers written in hexadecimal. It is not a signed integer simulator, a floating-point calculator, or a bitwise operations playground. If you need left shifts, AND masks, two's-complement interpretation by bit width, or arbitrary-precision math, you need a different tool than this one.
The divide operation is deliberately simple. It answers the question, how many whole times does B fit into A, and it drops any remainder. That is a useful behavior for chunk counts, page counts, block alignment checks, and classroom examples. It is not the same thing as full fractional division, and it does not expose the remainder separately.
The hex result format is also narrower than many users expect. The tool uses an unsigned 32-bit representation for the hex output. So if the decimal result is negative, the hex line can look like a wraparound number rather than a signed negative hex value. That is not a math error in the page. It is a formatting choice tied to the current implementation. The decimal result line is the safest place to confirm the signed outcome.
There is one more practical limit. JavaScript numbers can only represent integers exactly up to 9,007,199,254,740,991. Extremely large hex values above that safe range can lose precision before the operation even happens. For quick work with bytes, words, pages, offsets, and common homework values, this calculator is fine. For massive identifiers or strict 64-bit arithmetic, use a BigInt-aware developer workflow instead.
Common mistakes
- Typing characters outside 0 through 9 and A through F. A value like 0x1G is not valid hex.
- Assuming division returns a remainder or decimal fraction. This calculator only returns the integer quotient.
- Expecting negative subtraction results to display as signed hex. The decimal line can be negative while the hex line uses unsigned 32-bit formatting.
- Pasting values with spaces, underscores, commas, or sign characters. This parser accepts plain hex text and one optional 0x prefix only.
- Mixing up decimal and hex place values. 0x10 is sixteen, not ten.
- Using very large values and assuming JavaScript will keep every integer exact far beyond the safe range.
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