Free Antilog Calculator

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The antilogarithm reverses a logarithm: if log_b(x) = y, then the antilog of y (base b) gives back the original value x. Before electronic calculators were common, antilog tables were a standard tool used by engineers, scientists, and students to quickly compute powers without long multiplication — and the concept is still fundamental today in chemistry (converting pH back to hydrogen ion concentration), acoustics and electronics (converting decibel values back to raw power or amplitude ratios), and any field using logarithmic scales (like the Richter scale for earthquakes) where the actual underlying quantity needs to be recovered from its logarithmic representation.

How it works

Enter the log value (y) and the base (b, defaults to 10, matching the common/base-10 logarithm convention). Since antilog is defined as the inverse operation of taking a logarithm, the calculator computes b raised to the power y directly: antilog_b(y) = b^y.

Enter log value (y).
Enter base (b).
Click Calculate to see your results.

Examples

antilog base 10 of 3

10^3 = 1000 — reversing the fact that log₁₀(1000) = 3.

antilog base 2 of 5

2^5 = 32 — reversing the fact that log₂(32) = 5.

antilog base 10 of -2

10^-2 = 0.01 — a negative log value produces a result smaller than 1.

Common mistakes to avoid

Confusing the antilog with the natural exponential function e^y, which only applies when the base is e, not 10 or any other base.
Assuming the antilog "undoes" a logarithm of a different base than the one specified — the base used for antilog must match the base originally used to take the log.
Expecting a negative result from a negative log value — the antilog of a negative number is always a positive fraction less than 1, never negative itself.

Frequently asked questions

Base 10 is the default, matching the common (base-10) logarithm convention used on most scientific calculators and in most antilog tables historically.

Since pH is defined as -log₁₀[H⁺], recovering the actual hydrogen ion concentration [H⁺] from a known pH value requires taking the antilog: [H⁺] = 10^(-pH).

A result between 0 and 1 — since raising any positive base greater than 1 to a negative power always produces a fraction less than 1.

Yes — antilog works for any valid base you specify, though base 10 (common log) and base e (natural log, sometimes labeled "ln") are by far the two most frequently used in practice.

Since decibel values are defined using a base-10 logarithm of a power or amplitude ratio, converting a decibel measurement back into a raw ratio requires taking the antilog of the decibel value (divided by the appropriate scaling factor).

Always 1 — any nonzero base raised to the power 0 equals 1, matching the fact that log_b(1)=0 for any valid base b.

The antilog grows exponentially, since even a modest increase in y produces a dramatically larger b^y — this rapid growth is exactly what makes logarithmic scales useful for compressing huge ranges of values into manageable numbers.