Binary, Decimal and Hexadecimal Explained

Computers don't count the way we do. Understanding binary, decimal and hexadecimal helps a lot in programming and electronics.

Decimal (base 10)

The everyday system, using digits 0–9. Each position is a power of 10.

Binary (base 2)

Only 0s and 1s — the language of computers, because a circuit is either off (0) or on (1). The number 5 in binary is 101.

Hexadecimal (base 16)

Digits 0–9 then A–F. It's a compact way to write binary — every hex digit equals four binary digits. That's why colors in CSS use hex (like #10B981).

Convert between them

Use the Number Base Converter to switch between binary, octal, decimal and hex instantly, or the Text to Binary Converter to see how letters become 1s and 0s.