---
name: "ceill"
section: "3"
platform: "freebsd"
package: "base"
version: "16.0-CURRENT-20261027-61c70dc16a79"
release: "FreeBSD 16.0-CURRENT (2026-10-27)"
platforms: ["linux", "freebsd"]
url: "https://new.carta.tech/ceil"
---

# ceill(3)

smallest integral value greater than or equal to x

Part of [ceil(3)](/ceil/3.md).

## NAME

**ceil**, **ceilf**, **ceill** – smallest integral value greater than or equal to x

## LIBRARY

Math Library (libm, -lm)

## SYNOPSIS

**#include \<math.h\>**

*double*\

**ceil**(*double x*);

*float*\

**ceilf**(*float x*);

*long double*\

**ceill**(*long double x*);

## DESCRIPTION

The **ceil**(), **ceilf**() and **ceill**() functions return the smallest integral value greater than or equal to *x*, expressed as a floating-point number.

## SEE ALSO

[abs(3)](/abs/3.md), [fabs(3)](/fabs/3.md), [floor(3)](/floor/3.md), [ieee(3)](/ieee/3.md), [math(3)](/math/3.md), [rint(3)](/rint/3.md), [round(3)](/round/3.md), [trunc(3)](/trunc/3.md)

## STANDARDS

The **ceil**() function conforms to ISO/IEC 9899:1990 (“ISO C90”). The **ceilf**() and **ceill**() functions conform to ISO/IEC 9899:1999 (“ISO C99”).