Number Base Converter

From base

Value

Binary (2)

—

Octal (8)

—

Decimal (10)

—

Hexadecimal (16)

—

Common conversions

Decimal	Binary	Octal	Hex
0	0	0	0
1	1	1	1
2	10	2	2
8	1000	10	8
10	1010	12	A
16	10000	20	10
255	11111111	377	FF

What are binary numbers?

Binary numbers use only digits 0 and 1 (base 2). Computers use binary internally. Example: 1010 (binary) = 10 (decimal).

What are hexadecimal numbers?

Hexadecimal uses base 16 with digits 0–9 and letters A–F. Commonly used in programming for colors and memory addresses. Example: FF (hex) = 255 (decimal).

How do you convert between number systems?

Multiply each digit by the base raised to its position and sum. Example: 1010₂ = 1×2³ + 0×2² + 1×2¹ + 0×2⁰ = 8 + 0 + 2 + 0 = 10.