Adding hex: 1F + 2A
1F = 31, 2A = 42. Sum: 31 + 42 = 73 = 49₁₆. Or in hex: 1F + 2A: F+A=19, write 9 carry 1; 1+2+1=4. Result: 49₁₆. Common operation in CPU adders.
Hex Calculator - Free Online Calculator
Add, subtract, multiply or divide hexadecimal numbers and convert between hex, decimal, binary and octal. Hex is the standard notation for memory addresses, colour codes and binary data because each hex digit maps to exactly 4 bits.
- Formula shown on the page
- Runs in your browser
- Your inputs stay private
Digits 0-9, A-F (case-insensitive)
Digits 0-9, A-F (case-insensitive)
A in decimal
255
B in decimal
26
Result (hex)
119
Decimal
281
Binary
100011001
Octal
431
Understanding the Hex Calculator
Hexadecimal (base 16) is the compact notation programmers use for binary data. Memory addresses (0x7FFE3F2A), MAC addresses (00:1A:2B:3C:4D:5E), CSS colour codes (#FF5733), Bitcoin transaction hashes, JavaScript Object IDs, UUIDs - all use hex. Why hex over decimal? Because one hex digit equals exactly 4 binary bits - clean mapping that makes byte-level work fast and readable. Two hex digits = one byte = values 0-255. Four hex digits = 16 bits = 0-65,535. Eight hex digits = 32 bits = a memory address on a 32-bit system.
This calculator handles all four arithmetic operations on hex numbers plus modulo, with results shown in hex, decimal, binary and octal simultaneously. Indian B.Tech CSE/IT/ECE students study hex in digital electronics, computer organisation, and embedded systems courses. Software engineers use hex constantly when debugging memory issues, reading hex dumps, working with byte arrays, computing colour codes, or working with cryptographic hashes. The BigInt backend means you can compute on hex values of arbitrary length without overflow - useful for very large numbers like SHA-256 hashes (64 hex digits).
Using the Hex Calculator in 3 steps
Enter two hexadecimal numbers (0-9, A-F).
Pick an operation: +, −, ×, ÷, mod.
See the result in hex, decimal, binary and octal.
How the Hex Calculator works
Hex inputs are validated and parsed digit by digit. Each position is worth 16^n. The arithmetic happens in BigInt for accuracy, then the result is formatted in all four bases.
Formula
Hex uses base 16: digits 0-9 then A=10, B=11, …, F=15. FF₁₆ = 15×16¹ + 15×16⁰ = 255
- 0-9, A-FValid hex digits (case-insensitive)
- Each digitRepresents 4 binary bits
How the Hex Calculator gets its answer
Hex uses 16 digits: 0-9 followed by A, B, C, D, E, F (or lowercase a-f, equivalent). Each position represents a power of 16. Right to left: position 0 worth 1 (16⁰), position 1 worth 16 (16¹), position 2 worth 256 (16²), position 3 worth 4,096 (16³). So FF₁₆ = F×16 + F×1 = 15×16 + 15 = 255 in decimal.
Conversion between hex and binary is mechanical: each hex digit maps to exactly 4 bits. 0=0000, 1=0001, 2=0010, ..., 9=1001, A=1010, B=1011, C=1100, D=1101, E=1110, F=1111. So 3FA₁₆ = 0011 1111 1010₂. Reverse: group binary into 4-bit chunks from the right and convert each. This mapping is why programmers prefer hex - converting between hex and binary is trivial; between decimal and binary requires division.
Common uses: CSS colours use 6 hex digits (RRGGBB) representing 24-bit RGB - e.g., #FF5733 means red=FF (255), green=57 (87), blue=33 (51). Memory addresses on 64-bit systems use 16 hex digits (0x0000000000000000 to 0xFFFFFFFFFFFFFFFF). MAC addresses use 12 hex digits in 6 colon-separated pairs. UUIDs use 32 hex digits in 8-4-4-4-12 pattern. Each context just adopts hex for its byte-level convenience.
Worked examples
CSS colour #4A90E2 (light blue) RGB breakdown
Red: 4A₁₆ = 74. Green: 90₁₆ = 144. Blue: E2₁₆ = 226. In CSS: rgb(74, 144, 226). Reverse: any RGB tuple converts to a hex colour code.
32-bit memory address: 0xDEADBEEF
DEADBEEF₁₆ = 3,735,928,559 decimal = 11011110101011011011111011101111₂. Classic 'magic number' used by programmers to mark allocated memory. 32 bits = 8 hex digits.
When to use the Hex Calculator
- B.Tech CSE/IT/ECE - digital electronics, computer organisation homework.
- Software engineering - debugging hex dumps and byte arrays.
- Web development - CSS colour code computation.
- Networking - MAC and IPv6 address parsing.
- Cryptography - working with hash digests (SHA-256, MD5).
- Embedded systems - register values and memory layouts.
- Reverse engineering - analysing binary file formats.
- Game development - bit flags and colour blending.
Common mistakes and gotchas
- Treating A-F as 'invalid' decimal digits. In hex they're 10-15.
- Mixing up case sensitivity. Most parsers accept both upper and lowercase.
- Confusing hex with octal because both have non-decimal digit ranges.
- Forgetting that one byte = 2 hex digits, not one.
- Off-by-one errors when converting between hex and binary chunks.
Get more out of this tool
- Memorise hex digit values: A=10, B=11, C=12, D=13, E=14, F=15.
- Memorise key powers: 16²=256, 16⁴=65,536, 16⁸=4.29 billion.
- One hex digit = 4 bits. Two hex digits = 1 byte. Four hex digits = 2 bytes.
- For colour design, use online colour pickers that show both hex and RGB.
- Pair with the binary, octal-decimal-hex, and IP subnet calculators on this site for related base work.
Questions about the Hex Calculator
Why use hex when decimal exists?
Hex is a compact way to write binary. 8 bits (one byte) takes 8 binary digits but only 2 hex digits. Memory dumps and colour codes use hex for compactness.
How do colour codes work?
CSS colours like #FF5733 are 3 bytes - RR (red), GG (green), BB (blue), each 0-255 (00-FF in hex).
Can I use lowercase letters?
Yes - a-f and A-F are equivalent. The calculator normalises both to uppercase in the result.
What's the prefix 0x?
C/C++/JavaScript prefix 0x marks a hex literal. The calculator accepts hex digits directly without the prefix.
How do I convert hex to binary by hand?
Replace each hex digit with its 4-bit binary equivalent. F = 1111, A = 1010. So FA = 11111010.
Why do MAC addresses use hex?
Compact binary representation. A 48-bit MAC address would be unwieldy in binary (50 chars) but fits neatly in 12 hex digits.
Math in your browser
From simple percentages to scientific notation, statistics, geometry and big-number arithmetic - every common math problem you'd reach for a calculator for, runs in your browser with no installs. The fraction calculator preserves exact rationals, the big-number calculator uses BigInt for hundreds of digits without precision loss, and the scientific calculator's expression evaluator is a hand-written shunting-yard parser (no eval) that supports trig, log, factorial and parentheses.
If you're a student, double-check your work without paying for a graphing calculator. If you're a professional, use these tools as a sanity check on spreadsheet formulas. Every result is shown alongside its formula and inputs, so the math is always auditable.
The Hex Calculator is part of the Math suite on Online Calculator Tools, alongside 6 related calculators. All tools share the same UI patterns, the same privacy-first rendering (nothing is sent to a server), and the same commitment to showing the formula and assumptions behind every result.