Number Base Converter

Convert between decimal, binary, octal, and hexadecimal number systems.

Decimal (Base 10) 0-9
Binary (Base 2) 0b
Octal (Base 8) 0o
Hexadecimal (Base 16) 0x

Custom Base Conversion

Frequently Asked Questions

A number base (or radix) determines how many unique digits are used to represent numbers. Decimal uses 10 digits (0-9), binary uses 2 (0,1), octal uses 8 (0-7), and hexadecimal uses 16 (0-9, A-F).
Computers use binary because digital circuits have two states: on (1) and off (0). All data in computers, including numbers, text, and images, is ultimately stored and processed in binary.
Hexadecimal is commonly used in programming for memory addresses, color codes (#FF0000), MAC addresses, and anywhere binary data needs to be displayed compactly. Each hex digit represents exactly 4 binary digits.