# Antilog Calculator

URL: https://speedycalculator.com/calculators/math/antilog/
Last updated: 2026-10-30

> The antilog calculator finds the antilogarithm x = bʸ of a value y in base 10, e, 2 or any custom base – undoing a logarithm.

## Inputs

- Logarithm base
- Custom base
- Logarithm value y

## Results

- Antilog x = bʸ
- Order of magnitude (log₁₀ x)

## Formula

```
antilog_b(y) = bʸ
```

## Explanation

Taking the antilog reverses a logarithm. It turns pH back into hydrogen ion concentration, decibels back into intensity ratios and log-transformed statistics back into original units.

### How to use the Antilog Calculator

- **Logarithm base**
- **Custom base**
- **Logarithm value y**

Results update as you type, and everything is calculated in your browser.

### How it works

Choose the base and enter the logarithm y.

### Inputs explained

FieldWhat to enterLogarithm baseChoose one: 10 (common log), e (natural log), 2 (binary log), Custom baseCustom baseA numberLogarithm value yA number

### Example values

How the main result changes when **Custom base** changes and everything else stays at the example values above:

Custom baseAntilog x = bʸ2.5316.22783.75316.22785316.22786.25316.22787.5316.227810316.2278

## Worked example

Inputs — Logarithm base: 10 (common log); Logarithm value y: 2.5.

Results — **Antilog x = bʸ = 316.227766016838**; Order of magnitude (log₁₀ x) = 2.5.

## Key terms

- **Antilogarithm**: The number whose logarithm is given.

## FAQ

**What is the antilog of 2 (base 10)?**
100.

**What is the antilog of 1 in base e?**
e ≈ 2.71828.

**How do I get [H⁺] from pH?**
[H⁺] = 10^(−pH) mol/L.

**Is antilog the same as exponent?**
Yes – antilog_b(y) = bʸ.


## Sources

- [OpenStax – College Algebra 2e](https://openstax.org/details/books/college-algebra-2e)
- [OpenStax – Precalculus 2e](https://openstax.org/details/books/precalculus-2e)