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Logarithm Calculator

log of any value at any base, plus ln, log10, and log2.

log10(1000)
3.000000
ln (base e)
6.907755
log₁₀
3.000000
log₂
9.965784

x must be positive and base must be positive and not equal to 1. Computed as ln(x) / ln(base).

About

Enter x and a base, get log_base(x). Also shows the natural log, base-10 log, and base-2 log for the same value. Computed using the change-of-base formula.

How to use

  1. Enter x.
  2. Enter the base.
  3. Read the log and the alternate-base values.

FAQ

Why does it return an error sometimes?+

log is only defined for x > 0. The base must be positive and not equal to 1.