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.
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
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