Number Base Converter

Convert between bases 2 to 36, and see the working.

Method

To decimal: multiply each digit by its place value and add. Binary 1011 is 1×8 + 0×4 + 1×2 + 1×1 = 11.

From decimal: divide repeatedly by the target base, keeping each remainder, and read the remainders from the last one back to the first. The tool prints those divisions so the method can be checked by hand.

Digits above nine

Bases beyond ten need extra symbols, and letters continue the sequence: A is 10, B is 11, up to Z at 35. Hexadecimal therefore runs 0–9 then A–F, so hex FF is 15×16 + 15 = 255.

Why binary, octal and hex

Digital hardware is two-state, so base two is native. Octal and hexadecimal are shorthand for it: one octal digit is exactly three bits and one hex digit exactly four, so conversion is regrouping rather than arithmetic. That is why memory addresses and colour codes are written in hex.