How hex works
Hexadecimal is base-16, using digits 0-9 and letters A-F (where A=10, B=11, C=12, D=13, E=14, F=15). Each hex digit represents exactly 4 binary bits, which is why hex is the standard shorthand for binary data in programming.
Hex
A3F = A×162 + 3×161 + F×160 = 2,560 + 48 + 15 = 2,623Each hex digit directly maps to four binary digits: A=1010, 3=0011, F=1111. So A3F16 = 1010 0011 11112.
Common hex values
| Hex | Decimal | Binary | Common use |
|---|---|---|---|
| 0xFF | 255 | 1111 1111 | Max byte value |
| 0x100 | 256 | 1 0000 0000 | Byte overflow |
| 0xFFFF | 65,535 | 1111 1111 1111 1111 | Max 16-bit value |
| 0x7F | 127 | 0111 1111 | Max signed byte |
| 0xC0FFEE | 12,648,430 | 1100 0000 1111 1111 1110 1110 | Example word |
FAQ
Why is hex used in computing?
Each hex digit cleanly maps to 4 binary bits, making hex a compact, human-readable form for byte data. Two hex digits = one byte. That's why colours (#FF6B00), memory addresses, and MAC addresses use hex.
Is input case-sensitive?
No. Upper and lowercase letters are accepted. Output is always shown in uppercase.
What's the largest hex number I can enter?
The calculator uses BigInt, so there is no practical limit for integer values.