Logarithm Calculator

Free log, ln, custom base, and antilog calculator. Instant results, no sign-up.

Logarithm Calculator

Compute log (base 10), ln (base e), custom base, and antilog in one tool.

Result

log₁₀(100)

2

About the logarithm calculator

Free logarithm calculator with modes for common log (base 10), natural log (ln), any custom base, and antilog. Enter your values for instant results—no sign-up required.

  • log₁₀ (base 10) and ln (base e)
  • Custom base: log_b(x) for any base b
  • Antilog: compute base^exponent
  • Copy result and reset

Use cases

  • Algebra and calculus
  • Scientific and engineering math
  • Decibel and ratio calculations

For unit conversion (e.g. dB, ratios), use the Logarithmic converter.