Excel FLOOR Function

Related Functions:

CEILING Function
MROUND Function

Excel Rounding Functions

The Excel Floor function is one of fifteen rounding functions in Excel.

A full list, along with comparison tables, is provided on the Excel Rounding Functions page.

Function Description

The Excel FLOOR function rounds a supplied number towards zero to the nearest multiple of a specified significance.

The syntax of the function is:

FLOOR( number, significance )

Where the arguments are as follows:

number	-	The number that is to be rounded.
significance	-	The multiple of significance that the supplied number is to be rounded to. (This should generally have the same arithmetic sign (positive or negitive) as the supplied number argument).

Positive and Negative Arguments

Note: In Excel 2003 & 2007, the significance argument must have the same arithmetic sign (positive or negative) as the number argument. If they have different arithmetic signs, the Floor function returns an error.

However, in later versions of Excel, the Floor function has been improved, so that it can now handle a negative number argument and a positive significance argument. In this case, the Floor function reverses the direction of the rounding (i.e. rounds the supplied number away from zero).

Floor Function Examples

In column B of the following spreadsheet, the Excel Floor function is used to round the positive and negative numbers 26.75 and -26.75 to different multiples of significance.

Formulas:

	A	B
1	Number	Floor
2	26.75	=FLOOR( A2, 0.1 )
3	26.75	=FLOOR( A3, 0.5 )
4	26.75	=FLOOR( A4, 1 )
5	26.75	=FLOOR( A5, 10 )
6	26.75	=FLOOR( A6, 20 )
7	-26.75	=FLOOR( A7, -0.1 )
8	-26.75	=FLOOR( A8, -1 )
9	-26.75	=FLOOR( A9, -5 )

Results:

	A	B
1	Number	Floor
2	26.75	26.7
3	26.75	26.5
4	26.75	26
5	26.75	20
6	26.75	20
7	-26.75	-26.7
8	-26.75	-26
9	-26.75	-25

The above examples show how, when the number and the significance arguments have the same arithmetic sign, the Floor function rounds the supplied number towards zero.

Examples with Positive and Negative Arguments

Different combinations of positive and negative arguments, are shown in the spreadsheet below.

The results shown are those that would be obtained in current versions of Excel (2010 or later).

Formulas:

	A	B
1	Number	Floor
2	26.75	=FLOOR( A2, 1 )
3	26.75	=FLOOR( A3, -1 )
4	-26.75	=FLOOR( A4, 1 )
5	-26.75	=FLOOR( A5, -1 )

Results:

	A	B
1	Number	Floor
2	26.75	26
3	26.75	#NUM!
4	-26.75	-27	- returns an error in Excel 2007 & earlier
5	-26.75	-26

This example shows how:

In current versions of Excel (2010 and later), a negative number argument and a positive significance argument reverses the direction of the rounding (i.e. rounds the negative number away from zero) (see cell B4).
A positive number argument and a negative significance argument still results in an error in all versions of Excel (see cell B3).

For further details of the Excel Floor Function, see the Microsoft Office website.

Floor Function Errors

If you get an error from the Excel Floor function, this is likely to be one of the following:

Common Errors

#NUM!

Occurs:

In Excel 2010 or Excel 2013:	-	if the supplied number is positive and the supplied significance is negative.
In Excel 2007 or earlier:	-	if the supplied significance value has a different arithmetic sign to the supplied number argument.

#DIV/0!

Occurs if the supplied significance argument = 0.

#VALUE!

Occurs if one or both of the supplied arguments is non-numeric.

Return to the Excel Math Functions Page
Return to the List of All Built-In Excel Functions