🔢 Number Base Converter

Convert numbers between binary (base 2), octal (base 8), decimal (base 10), hexadecimal (base 16), and any custom base up to 36. Type in any field to convert instantly.

Binary — Base 2

Octal — Base 8

Decimal — Base 10

Hex — Base 16

Custom Base

Base: (2–36)

Online Number Base Converter — Binary, Octal, Decimal, Hex

Number base conversion is a fundamental concept in computer science. All data in a computer is stored in binary (base 2), but humans work with decimal (base 10). Hexadecimal (base 16) is used for memory addresses, color codes, and bytecode. Octal (base 8) is used in Unix file permissions (e.g., chmod 755).

Quick Reference

Decimal 255 = Binary 11111111 = Octal 377 = Hex FF. This is the maximum value of an 8-bit unsigned integer (one byte). Decimal 16 = Binary 10000 = Hex 10. Decimal 1024 (1 kilobyte) = Binary 10000000000 = Hex 400.

Hex Color Codes

CSS hex colors (#RRGGBB) encode red, green, and blue channels as two hex digits each. #FF0000 is pure red (R=255, G=0, B=0). #7c3aed is the purple accent used on this site (R=124, G=58, B=237).