Base 2 to base 10

Convert Binary to Decimal

Convert base 2 values to base 10. Integers remain exact even when they exceed JavaScript's ordinary safe-number limit.

Number From base

Result

42

To base

101010₂ = 42₁₀

Same value in common bases

Base	Value

Method

How to convert base 2 to base 10

Each binary digit is evaluated by its power of 2. The exact value is then repeatedly divided by 10 to produce the destination digits.

value₁₀ = sum(digit x 2^position)

For fractional digits, the converter keeps an exact rational numerator and denominator, then generates up to 32 destination digits. An ellipsis marks a repeating or longer expansion.

Examples

Binary to Decimal table

Binary (base 2)	Decimal (base 10)
1	1
10	2
1010	10
101010	42
1100100	100
11111111	255
10000000000	1024

Continue converting

Decimal to BinaryReverse conversion Binary to decimalBase 2 to base 10 Decimal to hexadecimalBase 10 to base 16