Number Base Reference
| Decimal | Binary | Octal | Hex |
|---|---|---|---|
| 0 | 0000 | 0 | 0 |
| 10 | 1010 | 12 | A |
| 15 | 1111 | 17 | F |
| 16 | 10000 | 20 | 10 |
| 255 | 11111111 | 377 | FF |
| 256 | 100000000 | 400 | 100 |
Frequently Asked Questions
Computers use binary (base 2) because electronic circuits have two states: on (1) and off (0). All data — text, images, code — is ultimately stored as binary. Hexadecimal is a convenient shorthand for binary since each hex digit represents exactly 4 bits.
0xFF is hexadecimal notation for 255 in decimal, or 11111111 in binary. The "0x" prefix indicates a hex number. In web colors, #FF0000 means 255 red, 0 green, 0 blue — pure red.