Developer converter

Number base converter

Convert integers and fractional values between bases 2 through 36. Long integers use exact arithmetic instead of floating-point approximations.

Number From base

Result

101010

To base

42₁₀ = 101010₂

Same value in common bases

Base	Value

Common bases

Popular base conversions

Binary to DecimalBase 2 to base 10 Decimal to BinaryBase 10 to base 2 Octal to DecimalBase 8 to base 10 Decimal to OctalBase 10 to base 8 Hexadecimal to DecimalBase 16 to base 10 Decimal to HexadecimalBase 10 to base 16 Binary to OctalBase 2 to base 8 Binary to HexadecimalBase 2 to base 16 Octal to BinaryBase 8 to base 2 Octal to HexadecimalBase 8 to base 16 Hexadecimal to BinaryBase 16 to base 2 Hexadecimal to OctalBase 16 to base 8

Method

How positional number bases work

A positional numeral uses each digit's position as a power of its base. Decimal 42 is 4 x 10 + 2; binary 101010 is 1 x 32 + 1 x 8 + 1 x 2, so both represent the same value.

Digits above 9 use letters A through Z, allowing bases up to 36. Letter case does not change the value.

Digit ranges

Base	Allowed digits
2 (binary)	0-1
8 (octal)	0-7
10 (decimal)	0-9
16 (hexadecimal)	0-9, A-F
36	0-9, A-Z

Complete directory

Base 2-36 conversions

Binary to Decimal Decimal to Binary Base 3 to Decimal Decimal to Base 3 Base 4 to Decimal Decimal to Base 4 Base 5 to Decimal Decimal to Base 5 Base 6 to Decimal Decimal to Base 6 Base 7 to Decimal Decimal to Base 7 Octal to Decimal Decimal to Octal Base 9 to Decimal Decimal to Base 9 Base 11 to Decimal Decimal to Base 11 Base 12 to Decimal Decimal to Base 12 Base 13 to Decimal Decimal to Base 13 Base 14 to Decimal Decimal to Base 14 Base 15 to Decimal Decimal to Base 15 Hexadecimal to Decimal Decimal to Hexadecimal Base 17 to Decimal Decimal to Base 17 Base 18 to Decimal Decimal to Base 18 Base 19 to Decimal Decimal to Base 19 Base 20 to Decimal Decimal to Base 20 Base 21 to Decimal Decimal to Base 21 Base 22 to Decimal Decimal to Base 22 Base 23 to Decimal Decimal to Base 23 Base 24 to Decimal Decimal to Base 24 Base 25 to Decimal Decimal to Base 25 Base 26 to Decimal Decimal to Base 26 Base 27 to Decimal Decimal to Base 27 Base 28 to Decimal Decimal to Base 28 Base 29 to Decimal Decimal to Base 29 Base 30 to Decimal Decimal to Base 30 Base 31 to Decimal Decimal to Base 31 Base 32 to Decimal Decimal to Base 32 Base 33 to Decimal Decimal to Base 33 Base 34 to Decimal Decimal to Base 34 Base 35 to Decimal Decimal to Base 35 Base 36 to Decimal Decimal to Base 36 Binary to Octal Binary to Hexadecimal Octal to Binary Octal to Hexadecimal Hexadecimal to Binary Hexadecimal to Octal Base 7 to Base 3 Base 3 to Base 7 Hexadecimal to Base 12 Base 12 to Hexadecimal