Number Base Converter
Convert numbers between any base from 2 to 36 with preset buttons for binary, octal, decimal and hexadecimal
Quick Presets
Valid characters: 0-9
Result in Base 2
11111111
Convert To
Common Number Bases
Base 10 (decimal): everyday counting, 0-9 digits. Base 2 (binary): computing, 0-1. Base 8 (octal): legacy computing, 0-7. Base 16 (hexadecimal): web colours, memory addresses, 0-9 + A-F. Convert between any pair: 255 in decimal = 11111111 in binary = 377 in octal = FF in hex.
Used in computing, networking, electronics. Programmers regularly switch between bases when working with bit-level operations, memory addresses, or hex colours. The mathematical concept is identical - same number, different representation. A scientific calculator typically supports DEC/BIN/OCT/HEX modes for direct conversion.
Common Number Base Conversions
| Decimal | Binary | Octal | Hex |
|---|---|---|---|
| 0 | 0 | 0 | 0 |
| 1 | 1 | 1 | 1 |
| 10 | 1010 | 12 | A |
| 16 | 10000 | 20 | 10 |
| 100 | 1100100 | 144 | 64 |
| 255 | 11111111 | 377 | FF |
| 1000 | 1111101000 | 1750 | 3E8 |
| 65535 | 1111...11111 | 177777 | FFFF |
Frequently Asked Questions
Why so many number systems?
Different uses. Binary suits computer hardware (on/off bits). Hex packs 4 binary digits into 1 hex digit (compact). Decimal suits human counting (10 fingers heritage). Octal was popular when computers had 6-bit or 12-bit words; less used now.
How do I convert by hand?
Decimal-to-binary: divide by 2 repeatedly, remainders read bottom-up. Binary-to-decimal: powers of 2, sum bits with their position weight. Hex-to-binary: each hex digit = 4 bits. Calculator does the work; understanding the process helps debug edge cases.