Logarithm calculator
Enter the number and the base: calculate the logarithm. For the natural log use base 2.718.
What is a logarithm
The logarithm in base b of a number x is the exponent b must be raised to in order to get x. For example log₁₀(1000) = 3, because 10³ = 1000.
Most used bases
Base 10 (decimal), base 2 (computing) and base e ≈ 2.718 (natural logarithm).