floor-floorf-floorl.md

title	description	ms.date	api_name	api_location	api_type	topic_type	f1_keywords	helpviewer_keywords	ms.assetid
floor, floorf, floorl	API reference for floor, floorf, and floorl; which calculates the floor of a value.	9/1/2020	floorf floorl floor _o_floor _o_floorf	msvcrt.dll msvcr80.dll msvcr90.dll msvcr100.dll msvcr100_clr0400.dll msvcr110.dll msvcr110_clr0400.dll msvcr120.dll msvcr120_clr0400.dll ucrtbase.dll api-ms-win-crt-math-l1-1-0.dll	DLLExport	apiref	floor floorl _floorl floorf	floor function floorf function calculating floors of values floorl function	e9955f70-d659-414f-8050-132e13c8ff36

floor, floorf, floorl

Calculates the floor of a value.

Syntax

double floor(
   double x
);
float floor(
   float x
); // C++ only
long double floor(
   long double x
); // C++ only
float floorf(
   float x
);
long double floorl(
   long double x
);
#define floor(X) // Requires C11 or higher

Parameters

x
Floating-point value.

Return value

The floor functions return a floating-point value that represents the largest integer that is less than or equal to x. There's no error return.

Input	SEH exception	_matherr exception
± QNaN, IND	none	_DOMAIN

floor has an implementation that uses Streaming SIMD Extensions 2 (SSE2). For information and restrictions about using the SSE2 implementation, see _set_SSE2_enable.

Remarks

C++ allows overloading, so you can call overloads of floor that take and return float and long double values. In a C program, unless you're using the <tgmath.h> macro to call this function, floor always takes and returns a double.

If you use the <tgmath.h> floor() macro, the type of the argument determines which version of the function is selected. See Type-generic math for details.

By default, this function's global state is scoped to the application. To change this behavior, see Global state in the CRT.

Requirements

Function	Required header
floor, floorf, floorl	<math.h>
floor macro	<tgmath.h>

For more compatibility information, see Compatibility.

Example

// crt_floor.c
// This example displays the largest integers
// less than or equal to the floating-point values 2.8
// and -2.8. It then shows the smallest integers greater
// than or equal to 2.8 and -2.8.

#include <math.h>
#include <stdio.h>

int main( void )
{
   double y;

   y = floor( 2.8 );
   printf( "The floor of 2.8 is %f\n", y );
   y = floor( -2.8 );
   printf( "The floor of -2.8 is %f\n", y );

   y = ceil( 2.8 );
   printf( "The ceil of 2.8 is %f\n", y );
   y = ceil( -2.8 );
   printf( "The ceil of -2.8 is %f\n", y );
}

The floor of 2.8 is 2.000000
The floor of -2.8 is -3.000000
The ceil of 2.8 is 3.000000
The ceil of -2.8 is -2.000000

See also

Math and floating-point support
ceil, ceilf, ceill
round, roundf, roundl
fmod, fmodf