Number Base Converter
Convert numbers between binary (base 2), octal (base 8), decimal (base 10), and hexadecimal (base 16).
Decimal (base 10)
Hexadecimal (base 16)
Binary (base 2)
Octal (base 8)
Convert numbers between binary (base 2), octal (base 8), decimal (base 10), and hexadecimal (base 16).
This tool converts numbers between the four most common number systems used in computing: decimal (base 10, everyday numbers), binary (base 2, how computers store data), hexadecimal (base 16, used for colors, memory addresses, and compact binary representation), and octal (base 8, used in Unix file permissions).
255 decimal = FF hex = 11111111 binary = 377 octal. Hexadecimal is especially useful because each hex digit represents exactly 4 binary digits, making it a compact way to write binary values. This is why colors in CSS use hex (#FF0000 for red) — each pair of hex digits represents one byte (0-255) for red, green, and blue channels.