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

# fmin(3)

determine minimum of two floating-point numbers

## NAME

fmin, fminf, fminl - determine minimum of two floating-point numbers

## LIBRARY

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

## SYNOPSIS

```
#include <math.h>
```

**double fmin(double** *x***, double** *y***);** **float fminf(float** *x***, float** *y***);** **long double fminl(long double** *x***, long double** *y***);**

Feature Test Macro Requirements for glibc (see [**feature\_test\_macros**(7)](/feature_test_macros/7.md)):

**fmin**(), **fminf**(), **fminl**():

```
    _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
```

## DESCRIPTION

These functions return the lesser value of *x* and *y*.

## RETURN VALUE

These functions return the minimum of *x* and *y*.

If one argument is a NaN, the other argument is returned.

If both arguments are NaN, a NaN is returned.

## ERRORS

No errors occur.

## ATTRIBUTES

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

| | | |
| --- | --- | --- |
| **Interface** | **Attribute** | **Value** |
| **fmin**(), **fminf**(), **fminl**() | Thread safety | MT-Safe |

## STANDARDS

C11, POSIX.1-2008.

## HISTORY

glibc 2.1. C99, POSIX.1-2001.

## SEE ALSO

[**fdim**(3)](/fdim/3.md), [**fmax**(3)](/fmax/3.md)