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Logarithm Calculator

Calculate the logarithm of a value for any base.

Worth Knowing

A logarithm answers the question 'what power produces this number?' — so log base 2 of 8 is 3 because 2³ equals 8. Logarithms turn multiplication into addition, the property that made slide rules and log tables the calculators of their era. They also compress huge ranges into manageable scales: the Richter scale, decibels, and pH are all logarithmic, so each whole-number step represents a tenfold change in the underlying quantity.

How to Use

  1. Enter Value into the first field of the Logarithm Calculator.
  2. Fill in the rest: Base.
  3. Your result appears instantly as you type — there's no submit button or page reload.

Frequently Asked Questions