In mathematics, the logarithm of a number is the exponent by which another fixed value, the base, must be raised to produce that number. For example, the logarithm of 1000 to base 10 is 3, because 1000 …

The base b logarithm of a number is the exponent that we need to raise the base in order to get the number. The logarithm of the multiplication of x and y is the sum of logarithm of x and logarithm of y. …

On a calculator it is the "log" button.

This free log calculator solves for the unknown portions of a logarithmic expression using base e, 2, 10, or any other desired base.

Simplify logarithmic expressions using algebraic rules step-by-step. AI may present inaccurate or offensive content that does not represent Symbolab's views. Save to Notebook!

To calculate the logarithm of a number x with base b, enter your values below. Did we solve your problem today? The log calculator (logarithm) calculates the value of a logarithm with an arbitrary base.

Jan 5, 2026 · Expressed mathematically, x is the logarithm of n to the base b if bx = n, in which case one writes x = log b n. For example, 2 3 = 8; therefore, 3 is the logarithm of 8 to base 2, or 3 = log 2 8.

For example the result for 2 x = 5 can be given as a logarithm, x = log 2 (5) . You will learn how to evaluate this logarithmic expression over the following lessons.

Learn the eight (8) log rules or laws to help you evaluate, expand, condense, and solve logarithmic equations. Try out the log rules practice problems for an even better understanding.

To avoid ambiguity, it is safest to use "log" to refer to base 10 logarithms and "ln" or "natural log" to refer to base e logarithms. In other words, "log (x)" typically indicates log 10 (x) and ln (x) indicates log e (x).