Number Base Converter
Enter a whole number in decimal.
This result is an estimate only. Double-check important figures before relying on them.
How it is calculated
- The number is written in base 2, 8, 16 and 32 using repeated division
- Hex digits above 9 are A to F
- Bits needed = the length of the binary form
For negative numbers, use the two’s complement calculator.
Worked example
255 in decimal:
- Binary 11111111
- Octal 377
- Hex FF
Why your number may differ
Only whole numbers up to 2⁵³ − 1 are supported, so very large values need a bigger tool.
Frequently asked questions
How do I convert decimal to binary?
Divide by 2 repeatedly and write the remainders from last to first. 13 gives 1101.
How do I convert decimal to hex?
Divide by 16 and use the letters A to F for remainders 10 to 15. 255 gives FF.
Why do programmers use hex?
One hex digit stands for exactly four bits, so hex is a short way to write binary values such as colours (#FF0000) and memory addresses.