Antilogarithm Calculator

This antilogarithm calculator finds the number that a logarithm points back to, giving you the antilog, also called the inverse log, without working it out by hand or reaching for old log tables. A logarithm asks what power you need to raise a base to in order to reach a given number; the antilogarithm reverses that question, taking the power and the base and returning the result. You enter two values: the logarithm value (L) and the base (b), for example 2 and 10. The calculator works out b raised to the power L and shows it as the main result, alongside the natural antilog (e^L, using Euler's number as the base) and the base you chose, so you can compare common and natural results at a glance. This is handy whenever you need to undo a log calculation, such as converting a pH reading, a decibel level or a Richter magnitude back into its original linear value, or when checking working from a maths or science course. Simply type in your logarithm value and base and the result updates instantly as you go. Keep in mind the base must be a positive number other than 1, since logarithms and antilogs are undefined otherwise. Results are rounded for display, so very large or very small antilogs may appear in a shortened rather than fully precise form.

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Logarithm value (L)

Base (b)

Natural antilog (e^L)

Base

The formula

The antilogarithm of L in base b is b raised to the power L, that is antilog_b(L) = b^L. With base 10 it is 10^L, and the natural antilog is e^L. It is the inverse of the logarithm.

Worked example

The base 10 antilog of 2 is 10^2 = 100, because log base 10 of 100 is 2. The natural antilog of 2 is e^2, about 7.389056. Enter 2 and 10 to confirm.

Frequently asked questions

What is an antilogarithm?

The inverse of a logarithm. The antilog of L in base b is b to the power L, undoing the log.

What is the antilog of 2 in base 10?

100, since 10 squared is 100.

What base should I use?

Use 10 for common logs, e for natural logs, or any positive base other than 1 to match your log.

Who this calculator is for

This calculator is for students and anyone needing a quick, reliable result.

What this calculator assumes

You enter valid numbers.
The standard formula is applied.
Results are rounded for display.

Formula and sources

Related calculators

Scientific Calculator: general scientific maths.
Percentage Calculator: percentages and changes.
Ratio Calculator: simplify and scale ratios.

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