Number Base Converter
Enter a number in any base below — the other three update live.
Where each base is used
Decimal is everyday counting. Binary is how computers represent everything at the hardware level. Hexadecimal is a compact stand-in for binary — each hex digit maps to exactly 4 bits — and shows up in color codes, memory addresses, and hashes. Octal is less common today but still appears in Unix file permissions.
About the Number Base Converter
The Number Base Converter converts between decimal, hexadecimal, octal and binary at the same time. Type in any field and the other three update immediately, which is helpful for programming, networking and electronics.
Computers use binary (base 2) internally. Hexadecimal (base 16) is a compact way to write binary, with each hex digit representing four bits. Octal (base 8) is used in Unix file permissions. Decimal (base 10) is how people usually write numbers. For example, decimal 255 is binary 11111111, octal 377 and hexadecimal FF.
How to use it
- Type a number in any of the four fields.
- The other fields update.
- Check digits are valid for the base.
- Copy the value you need.
Tips and good to know
- Hex digits above 9 are A to F.
- Binary only uses 0 and 1.
- Use uppercase or lowercase hex consistently.
Frequently asked questions
How do I convert 1010 binary to decimal?
It is 10.
Does it support negative numbers?
It is intended for non-negative integers.
Is there a maximum?
Very large numbers may lose precision.