Antilog Calculator
Find the antilogarithm of a number for any base.
Results update as you type.
How it works
The antilogarithm, or antilog, is the inverse of a logarithm, and this calculator finds it for any base. You enter a logarithm value and, optionally, a base; if you leave the base blank it defaults to ten, the common logarithm. The antilog simply raises the base to the power of the value you enter, undoing what a logarithm does. Where a base-ten logarithm asks what power of ten gives a number, the antilog takes that power and returns the number, so the antilog of two in base ten is one hundred. Antilogs are essential whenever you need to recover an original value from its logarithm, which happens across science and engineering. The decibel scale, the pH scale, the Richter scale for earthquakes, and many signal and acoustics calculations store quantities as logarithms, and you take the antilog to get back to the real value. Using base e, about 2.718, gives the natural antilog, the exponential function, central to growth, decay, and compound interest. You can use any positive base. Enter the logarithm value and, if needed, a base other than ten to compute the antilogarithm.
antilog_b(x) = bˣ
The antilogarithm reverses a logarithm: the antilog of x in base b is simply b raised to the power x. Since a logarithm asks what exponent turns the base into a number, the antilog does the opposite, taking that exponent back to the number. The default base is ten, so the antilog of two is ten squared, which is one hundred.
Source:Algebra
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Worked example
How to use this calculator
- 1
Enter your values
Enter logarithm value.
- 2
Adjust the options
Adjust base (default 10) if they apply — sensible defaults are already set.
- 3
Read your result
Antilog updates instantly as you type — no button to press.
Frequently asked questions
What is an antilogarithm?
An antilogarithm is the inverse operation of a logarithm. If the logarithm of a number is a certain value, the antilog of that value returns the original number. It is computed by raising the base to the power of the logarithm value. In base ten, the antilog of three is ten cubed, which is one thousand.
How do I calculate an antilog?
Raise the base to the power of the logarithm value. For a common, base-ten log, the antilog of a number x is ten to the power x. Enter the value and the base into the calculator, or leave the base blank to use ten by default, and it evaluates the power for you instantly.
What is the antilog in base e?
The antilog in base e, where e is about 2.718, is the exponential function, e raised to the power of the value. It is the inverse of the natural logarithm. To compute it here, enter your value and set the base to e's value, roughly 2.718, or more precisely as needed for your calculation.
Where are antilogs used?
Antilogs recover real values from logarithmic scales used across science: converting decibels back to power ratios, pH back to hydrogen-ion concentration, Richter magnitudes back to amplitude, and log-transformed data back to original units. Any field that stores or calculates in logarithms relies on the antilog to return to ordinary numbers.
What is the relationship between log and antilog?
Logarithm and antilogarithm are inverse operations that undo each other. Taking the log of a number and then the antilog returns the original number, and vice versa, provided the same base is used. This inverse relationship is why antilogs are needed to reverse any calculation performed in a logarithmic scale.