Convert between binary, octal, decimal and hex
Enter a whole number in any of the four number systems and see it instantly converted to the other three, along with the bits and bytes it needs — every conversion runs through BigInt so long numbers stay exact.
How to use
- Select which base you're entering the number in
- Type the number (up to 256 digits)
- Read all four base representations at once, with the place-value working shown below
Common questions
Can I convert a number with a decimal point, like 10.5?
No — this converter works with whole numbers only, across all four bases (binary, octal, decimal, hexadecimal). For a decimal number with a fractional part converted to binary, use the separate Decimal to Binary tool instead.
How large a number can I convert?
Up to 256 digits in whichever base you're converting from. Every conversion runs through BigInt arithmetic, so even very long binary or hex strings convert exactly rather than losing precision.