---
name: "clog10"
section: "3"
platform: "linux"
package: "man-pages"
version: "6.19-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/clog10"
---

# clog10(3)

base-10 logarithm of a complex number

## NAME

clog10, clog10f, clog10l - base-10 logarithm of a complex number

## LIBRARY

Math library (*libm*, *-lm*)

## SYNOPSIS

```
#define _GNU_SOURCE         /* See feature_test_macros(7) */
#include <complex.h>
```

**double complex clog10(double complex** *z***);** **float complex clog10f(float complex** *z***);** **long double complex clog10l(long double complex** *z***);**

## DESCRIPTION

The call *clog10(z)* is equivalent to:

```
clog(z)/log(10)
```

or equally:

```
log10(cabs(c)) + I * carg(c) / log(10)
```

The other functions perform the same task for *float* and *long double*.

Note that *z* close to zero will cause an overflow.

## ATTRIBUTES

For an explanation of the terms used in this section, see [**attributes**(7)](/attributes/7.md).

| | | |
| --- | --- | --- |
| **Interface** | **Attribute** | **Value** |
| **clog10**(), **clog10f**(), **clog10l**() | Thread safety | MT-Safe |

## STANDARDS

GNU.

## HISTORY

glibc 2.1.

The identifiers are reserved for future use in C99 and C11.

## SEE ALSO

[**cabs**(3)](/cabs/3.md), [**cexp**(3)](/cexp/3.md), [**clog**(3)](/clog/3.md), [**clog2**(3)](/clog2/3.md), [**complex**(7)](/complex/7.md)