How this calculator works
An antilogarithm reverses a logarithm. Select the missing quantity and enter the other two. The base must be positive and different from one, and the antilogarithm must be positive. A logarithm of zero corresponds to an antilogarithm of one for every allowed base, so it cannot determine a unique base.
Formula
x = b^y; y = ln(x)/ln(b); b = x^(1/y) when y is non-zero.
Worked example
With base 2 and logarithm 3, the antilogarithm is 8 because 2 times 2 times 2 is 8. With base 10 and logarithm -2, the answer is 0.01.
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Frequently asked questions
Is antilog always base 10?
No. Base 10 is common, but any positive base other than one is allowed.
Can the logarithm be negative?
Yes. For bases above one, negative logarithms produce numbers between zero and one.
Why does a very large exponent fail?
The numeric output must be finite and non-zero. Exponents beyond floating-point range cannot be displayed reliably.