Calculate logarithm with any base — log₁₀, natural log (ln), log₂, or any custom base. Also calculates antilog.
A logarithm answers: to what power must the base be raised to get a given number? log₁₀(100) = 2 because 10² = 100.
ln (natural log) uses base e ≈ 2.718. log₁₀ uses base 10. Both are widely used in science, engineering, and finance.
Enter the number and select the base (10, e, or custom). Click Calculate to get the logarithm instantly.