Number Base Converter — bin, oct, dec, hex

This tool instantly converts numbers between the four main numeral systems used in programming and computer science.

Numeral systems

• Binary (bin, 2) — digits 0 and 1, used in computer architecture;
• Octal (oct, 8) — digits 0–7, used in Unix file permissions;
• Decimal (dec, 10) — the familiar base-10 system;
• Hexadecimal (hex, 16) — digits 0–9 and A–F, widely used in CSS colors and memory addresses.