Excel FLOOR.MATH Function

Related Functions:

Excel Rounding Functions

The Excel Floor.Math 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.Math function rounds a supplied number down to a supplied multiple of significance.

In general, positive values are rounded towards zero and negative numbers are rounded away from zero. However, the user can reverse the direction of the rounding for negative numbers.

Note: the Floor.Math function was first introduced in Excel 2013 and so is not available in earlier versions of Excel.

The syntax of the function is:

FLOOR.MATH( number, [significance], [mode] )

Where the arguments are:

number

The number that is to be rounded down.

[significance]

An optional argument that specifies the multiple of significance to round the supplied number to.

If omitted, the [significance] argument takes on the default value 1 (i.e. round down to the nearest integer).

(Note that the arithmetic sign of the [significance] argument is ignored).

[mode]

An optional numeric argument that reverses the direction of rounding for negative numbers only.

If [mode] = 0 (or is omitted), negative numbers are rounded away from zero.
If [mode] = any other numeric value, negative numbers are rounded towards zero.

Floor.Math Function Examples

In column B of the following spreadsheet, the Excel Floor.Math function is used to round down the positive and negative numbers 58.55 and -58.55, to different significance values.

Formulas:

	A	B
1	58.55	=FLOOR.MATH( A1 )
2	58.55	=FLOOR.MATH( A2, 0.1 )
3	58.55	=FLOOR.MATH( A3, 5 )
4	-58.55	=FLOOR.MATH( A4, 1 )
5	-58.55	=FLOOR.MATH( A5, 1, 1 )
6	-58.55	=FLOOR.MATH( A6, 10 )

Results:

	A	B
1	58.55	58
2	58.55	58.5
3	58.55	55
4	-58.55	-59
5	-58	-58
6	-58.55	-60

The above examples show how:

If the [significance] argument is omitted, it takes on the default value of 1 (see cell B1).
The Floor.Math function generally rounds positive numbers towards zero and negative numbers away from zero. However, if the [mode] argument is provided and is non-zero, negative numbers are rounded towards zero (see cell B5).

For further information and examples of the Excel Floor.Math function, see the Microsoft Office website.

Floor.Math Function Error

If you get an error from the Excel Floor.Math function, this is likely to be the #VALUE! error:

Common Error

#VALUE!

Occurs if any of the supplied arguments are non-numeric.

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