basic

Logarithm Calculator

Natural log, log base 10, and arbitrary-base logarithm.

Compute the logarithm of any positive number in any base — change-of-base formula included.

Daniel Oh By Daniel Oh
Published Last reviewed 1 min read

Inputs

Results

Enter values and click Calculate to see results.
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How to use this calculator

  1. Fill in the inputs above using the units you already have.
  2. Values update automatically as you type — no submit button needed.
  3. Hover any result row for the underlying formula and intermediate values.

Formula

logb(x) = ln(x) / ln(b)

In depth

Compute the logarithm of any positive number in any base — change-of-base formula included.