FLOOR(3) | Library Functions Manual | FLOOR(3)

# NAME

`floor`, `floorf`, `floorl` — round to largest integral value not greater than x

# SYNOPSIS

Math Library (libm, -lm)
`#include <math.h>`

double
`floor`(double x);

float
`floorf`(float x);

long double
`floorl`(long double x);

# DESCRIPTION

The `floor`() function returns the largest integral value less than or equal to x. The `floorf`() function is a single precision version of `floor`(). The `floorl`() function is an extended precision version of `floor`().

# SEE ALSO

abs(3), ceil(3), fabs(3), nextafter(3), rint(3)

# STANDARDS

The `floor`() function conforms to ANSI X3.159-1989 (“ANSI C89”).

# HISTORY

A `floor`() function first appeared in Version 5 AT&T UNIX.

June 7, 2025 | Debian