CEIL(3) | Library Functions Manual | CEIL(3)

# NAME

`ceil`, `ceilf`, `ceill` — round to smallest integral value greater than or equal to x

# SYNOPSIS

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

double
`ceil`(double x);

float
`ceilf`(float x);

long double
`ceill`(long double x);

# DESCRIPTION

The `ceil`() function returns the smallest integral value greater than or equal to x. The `ceilf`() function is a single precision version of `ceil`(). The `ceill`() function is an extended precision version of `ceil`().

# SEE ALSO

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

# STANDARDS

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

June 7, 2025 | Debian