Number Base Converter
Convert whole numbers between binary, octal, decimal, hexadecimal and any base up to 36, including very large values.
Runs in your browser. Nothing is uploaded Free, no sign-up Works on mobile
Number
Input base
Binary (base 2)
1111 1111
Octal (base 8)
377
Decimal (base 10)
255
Hexadecimal (base 16)
FF
Custom base
73
Bits needed: 8. Arbitrarily large integers are supported.
How to use Number Base Converter
- Type the number.
- Choose the base it is written in.
- Read the number in every other base and copy what you need.
Frequently asked questions
How do I convert decimal to binary?
Divide by 2 repeatedly and write the remainders in reverse. 13 → 1101. The converter does this instantly for any size.
What is hexadecimal used for?
Hex (base 16) is a compact way to write binary data. It is used for colours (#FF8800), memory addresses and byte values.
Related tools
All Everyday Calculators →- Binary / Hex Text Converter See the bytes behind any text, or decode binary and hex back into readable text.
- Scientific Calculator A full scientific calculator in your browser.
- Prime Number Checker Test whether a number is prime, break composite numbers into prime factors, and list the primes in any range.
- GCD & LCM Calculator Calculate the highest common factor and lowest common multiple of any set of whole numbers, with the division steps shown.
- Quadratic Equation Solver Enter a, b and c to solve any quadratic equation, including equations with complex roots.
- Probability Calculator Solve probability problems: single events, two independent events, combinations and permutations, and binomial distributions.