Inverse Logarithm Calculator
Reversing the Log
If a logarithm asks "what power gives me this number," the inverse logarithm — the antilog — answers the reverse question: given this power, what number does it produce? Practically, that just means exponentiation, but framing it as an "antilog" mode makes it easy to reverse a log-scale result (like a pH reading or a decibel value) back into its original quantity without manually rewriting the exponent.
The Formulas
Common Antilog: antilog(x) = 10^x
Custom Base Antilog: antilog_b(x) = b^x
Each mode is a direct exponentiation using the corresponding base — Euler's number (e ≈ 2.71828) for natural antilogs, 10 for common antilogs, or any custom base greater than zero and not equal to 1.
Where This Is Used
- Chemistry — converting a pH value back into hydrogen ion concentration.
- Acoustics — converting a decibel level back into a raw amplitude ratio.
- Finance — reversing a continuously compounded growth rate back into a total value.
- Data analysis — un-transforming log-scaled data back into its original units before further calculation.
| Expression | Result |
|---|---|
| e^1 | 2.718282 |
| e^2 | 7.389056 |
| 10^3 | 1,000 |
How to Use This Calculator
- Choose a mode: Natural Antilog, Common Antilog, or Custom Base Antilog.
- Enter the Log Value (x).
- For Custom Base, also enter the Base.
- Select Calculate to see the resulting value.
Related Calculations
Need to go the other direction? The Logarithm Calculator computes natural, common, and custom-base logs, and the Exponent Calculator raises any base to any power directly.