Binary Converter
Convert binary to decimal, and to every other common base at the same time.
Base 10255from 11111111 in base 2
Decimal value255
Digits3
The same value in every common base
| System | Value |
|---|---|
| Binary (base 2) | 11111111 |
| Octal (base 8) | 377 |
| Decimal (base 10) | 255 |
| Hexadecimal (base 16) | FF |
| Base 36 (base 36) | 73 |
How base conversion works
A number written in base b gives each digit a place value that is a power of b. Reading 1101 in binary, for example:
1×2³ + 1×2² + 0×2¹ + 1×2⁰ = 8 + 4 + 0 + 1 = 13
Going the other way, you repeatedly divide by the target base and collect the remainders from last to first.
Bases you will actually meet
- Binary (2) — how hardware stores everything.
- Octal (8) — still used for Unix file permissions.
- Decimal (10) — the everyday base.
- Hexadecimal (16) — compact for bytes and colours; two hex digits are exactly one byte.
Bases above 10 borrow letters for the extra digits, so hex runs 0-9 then A-F. This calculator accepts an optional 0x, 0b or 0o prefix and ignores spaces and underscores.