Number Base Converter

Convert numbers between binary, octal, decimal and hexadecimal — live as you type.

Binary (base 2)

Octal (base 8)

Decimal (base 10)

Hexadecimal (base 16)

Type in any field — the others update live.

Number bases explained

Why do programmers use hex?

One hex digit = 4 bits, so bytes map neatly to 2 hex digits — compact and readable.

What is 255 in binary?

11111111 — eight ones, the max value of one byte.

Can it handle negative numbers?

This tool converts non-negative integers; negatives use two's complement in real systems.