Logarithm Calculator
Calculate the logarithm of a number in base 10, base e (natural log), base 2, or any custom base.
Result
2.000000
Comment ça marche
Uses the change-of-base formula log_b(x) = ln(x) / ln(b) to support any base, with shortcuts for the common bases 10, e, and 2.
Why must the input be positive?
Logarithms are only defined for positive real numbers — log(0) and log of negative numbers have no real result.