# log10() Function & Examples

Use the log10() arithmetic function in Calcul.io. Review its syntax, edit working examples, understand the result, and explore related math functions.

## log10

#### log10(x)

Try it yourself:

```calculio
log10(0.00001)
log10(10000)
10 ^ 4
log(10000) / log(10)
log(10000, 10)
```

[exp](https://calcul.io/function/exp/index.md)

[log](https://calcul.io/function/log/index.md)

---

## log10(): Base-10 Logarithm

**log10()** returns the exponent of 10 needed to produce a positive input. It is natural for orders of magnitude, decibels, pH-style scales, and scientific notation.

## Positive inputs only

For real results, the input must be greater than zero. log10(1000) is 3 and log10(0.1) is −1. Use [pow()](https://calcul.io/function/pow/index.md) to reverse a base-ten exponent, or [log()](https://calcul.io/function/log/index.md) when natural logarithms suit the formula.

Keep units meaningful by dividing a measurement by a reference before taking a logarithm. Use [abs()](https://calcul.io/function/abs/index.md) only when a magnitude, rather than a signed measurement, is the intended input.

[All functions](https://calcul.io/functions/index.md)