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FLOOR.MATH Function

Excel 2013+

Summary

The FLOOR.MATH function in Excel rounds a number down to the nearest integer or to the nearest multiple of a specified value. It provides precise control over rounding direction, especially for negative numbers, making it ideal for financial calculations and data alignment tasks.

Syntax

FLOOR.MATH(number, significance, mode)

Parameters

Parameter	Type	Required	Description
number	`Number`	Yes	The numeric value you want to round down to a multiple
significance	`Number`	No	The interval multiple for rounding (defaults to 1)
mode	`Number`	No	Controls negative number rounding: positive/omitted = away from zero, negative/zero = toward zero

Using the FLOOR.MATH Function

FLOOR.MATH excels at consistent downward rounding for pricing tiers, financial buckets, and data categorization. Unlike basic FLOOR, it offers mode control for negative values and works intuitively with various significance levels for professional number formatting.

Common FLOOR.MATH Examples

Basic Rounding to Nearest Integer

=FLOOR.MATH(6.7)

Rounds 6.7 down to 6 using default significance of 1.

Round to Multiple of 5

=FLOOR.MATH(24.3,5)

Rounds 24.3 down to nearest multiple of 5, resulting in 20.

Negative Number Default Behavior

=FLOOR.MATH(-8.1,2)

Rounds -8.1 away from zero to nearest even multiple (-10).

Negative Number Toward Zero

=FLOOR.MATH(-5.5,2,-1)

Rounds -5.5 toward zero to nearest even multiple (-4).

Frequently Asked Questions

It defaults to 1, rounding down to the nearest integer.

Positive/omitted = round away from zero (more negative); 0 or negative = round toward zero.

No, significance should be positive. Use absolute values.

Common Errors and Solutions

#NUM! error

Cause: Invalid significance (negative or zero when inappropriate)

Solution: Use positive significance values greater than zero

#VALUE! error

Cause: Non-numeric input for number parameter

Solution: Ensure number argument contains valid numeric data

Notes

By default positive decimals round toward zero, negatives round away from zero
Mode parameter only affects negative numbers
Integer inputs return unchanged
Works with decimal significance values

Compatibility

Available in: Excel 2013, Excel 2016, Excel 2019, Excel 2021, Microsoft 365

Not available in: Excel 2010 and earlier

Content last reviewed: December 9, 2025
Update frequency: As needed
Excel versions tested: Excel 2013+