Number Base Conversions
Convert number bases — binary, decimal, hexadecimal, octal. Free calculators for programming, electronics, and computer science.
4 units · 6 conversions
Number bases define how many digits are available before place value rolls over. Decimal (base 10) is everyday math; binary (base 2) is the language of digital circuits; hexadecimal (base 16) compactly represents binary for programmers.
Converting between bases is not multiplication — it is positional notation. Each digit's value depends on its place. Our calculators handle binary ↔ decimal ↔ hex ↔ octal pairs used in software development and digital logic courses.
Popular number base conversions
Real-world example
A debugger shows memory address 0x2A and you need the decimal value. Converting hexadecimal 2A to decimal gives 42 — useful when reading datasheets or network masks.
All number base conversions
Number Base units explained
- Binary (bin)
- Also: binary, base-2
- Octal (oct)
- Also: octal, base-8
- Decimal (dec) · base unit
- Also: decimal, base-10
- Hexadecimal (hex)
- Also: hexadecimal, base-16, hex
Frequently asked questions
- How do I convert binary to decimal?
- Multiply each bit by 2 raised to its position and sum. Example: 1010₂ = (1×8)+(0×4)+(1×2)+(0×1) = 10.
- Why do programmers use hexadecimal?
- One hex digit represents exactly four binary bits, making long binary strings easier to read and write.