Binary Converter
Type a number in any base — decimal, binary, octal or hexadecimal — and see all four at once.
About this tool
Computers store everything as binary — ones and zeroes — but humans read decimal, programmers read hex, and file permissions speak octal. This converter translates a whole number between all four bases at once; change the input base and type, and every representation updates.
One honest limit: this tool handles whole numbers (integers). Fractional values in other bases involve rounding choices, so they are deliberately left out rather than shown wrong.
How to use it
- Choose the base of the number you are typing.
- Type the number — all four bases update as you type.
Frequently asked questions
Why is hex so common in programming?
One hex digit represents exactly 4 binary digits, so a byte is always two hex digits. Hex is the compact way to write binary data — colours (#FF5733), memory addresses and MAC addresses all use it.
What is octal used for?
Octal (base 8) survives mainly in Unix file permissions — chmod 755 is octal — and in some older computing contexts.
Can it convert negative or fractional numbers?
No — this converter is for whole numbers. Negative and fractional base conversion needs sign and rounding conventions that deserve their own explanation rather than a silent guess.