Free online number base converter

How to use

1. Type the number to convert in the Value field.
2. Set From base to the current base of your number.
3. Set To base to the target base.
4. Results update automatically — no button needed.

Formulas

To parse a value in base b:

decimal = sum of (digit × b^position) for each digit, right to left

To express a decimal integer n in base b:

repeatedly divide n by b, collecting remainders right-to-left

Worked example

Convert 255 (decimal) to hexadecimal:

255 ÷ 16 = 15 remainder 15 → F
15  ÷ 16 = 0  remainder 15 → F
Read remainders right-to-left → FF

Convert FF (hex) to binary:

F = 1111 in binary
FF = 11111111 in binary (8 bits)

Standard representations