Number base converter
Convert a whole number between binary, octal, decimal, hexadecimal and any base from 2 to 36.
How it works
The digits are read from left to right: value = value × base + digit. To write the value in another base it is divided by that base repeatedly; the remainders, read backwards, are the digits.
Worked example
- 255 ÷ 16 = 15 remainder 15 (F)
- 15 ÷ 16 = 0 remainder 15 (F)
- 255 = 0xFF = 0b11111111
Frequently asked questions
How do I read a hexadecimal number?
Each digit is worth 16 times the one to its right, with A–F standing for 10–15. 0x2F = 2 × 16 + 15 = 47.
Can I type 0x, 0b or 0o?
Yes. A 0x, 0b or 0o prefix picks hexadecimal, binary or octal automatically; spaces and underscores between digits are ignored.
How large can the number be?
Practically any size: whole numbers are handled with BigInt, so a 100-digit number converts exactly. Fractions and negative numbers in other bases are not supported.