Number Base Converter
Convert numbers between Decimal, Binary, Octal, and Hexadecimal. Edit any field to convert all others.
Number Base Conversion Guide
Computers store and process numbers in binary (base 2), but we typically work with decimal (base 10). Hexadecimal (base 16) and octal (base 8) are common in computing as compact representations of binary values. This tool lets you instantly convert between all four bases — just type in any field and the rest update automatically.
Number System Reference
| System | Base | Digits | Example |
|---|---|---|---|
| Decimal | 10 | 0–9 | 255 |
| Binary | 2 | 0–1 | 11111111 |
| Octal | 8 | 0–7 | 377 |
| Hexadecimal | 16 | 0–9, A–F | FF |
Where Each Base Is Used
Binary (Base 2)
The native language of all computers. CPU instructions, memory addresses, and network data are binary at the hardware level.
Octal (Base 8)
Unix/Linux file permissions (chmod 755), legacy PDP systems, and some assembly languages use octal for compactness.
Hexadecimal (Base 16)
CSS colors (#FF5733), memory addresses, RGB values, SHA hashes, and bytecode are all expressed in hex.
Decimal (Base 10)
Human-readable number system used in most programming languages for integer literals and user-facing number display.