Binary, Decimal, Hex Converter
Convert numbers between binary (base 2), decimal (base 10), hexadecimal (base 16), and octal (base 8).
Or use the standard form below
What is Binary, Decimal, Hex Converter?
The binary/hex converter handles the number-base conversions used in programming, networking, and digital logic.
How it works
Each base uses its set of digits: binary 0–1, octal 0–7, decimal 0–9, hex 0–9 + A–F. Converting any number works by repeated division.
Worked example
Decimal 255 = 11111111 binary = 377 octal = FF hex. Common because it's the maximum byte value (2⁸ − 1).
How to use this calculator
- Type the number.
- Pick the base of your input.
- All three other bases appear.
Frequently asked questions
Why is hex used in programming?
Hex is base 16 = 2⁴, so each hex digit represents exactly 4 bits. A byte (8 bits) is two hex digits. This makes hex the most compact human-readable format for binary data.
What's the 0x prefix?
Conventional prefixes: 0x for hex (0xFF = 255), 0b for binary, 0o for octal, no prefix for decimal. C, Python, JavaScript all use these.
Why use binary?
Computers store everything as binary (electronic on/off states). Programmers see binary when working with bit flags, low-level networking, encryption, and embedded systems.
What about negative numbers?
This calculator handles unsigned (positive) integers. Negative integers in binary use "two's complement" — a different representation. Most programming contexts use unsigned for converters.