How to use the Excel FLOOR function

Summary

The Excel FLOOR function rounds a given number down to the nearest specified multiple. FLOOR works like the MROUND function, but FLOOR always rounds down.

Purpose

Round a number down to the nearest specified multiple

Return value

A rounded number.

Syntax

=FLOOR (number, significance)

Arguments

number - The number that should be rounded.
significance - The multiple to use when rounding.

Usage notes

The Excel FLOOR function rounds a number down to a given multiple. The multiple to use for rounding is provided as the significance argument. If the number is already an exact multiple, no rounding occurs and the original number is returned.

FLOOR works like the MROUND function, but unlike MROUND, which rounds to the nearest multiple, FLOOR always rounds down.

Example #1 - round down to nearest 5

To round a number in A1 down to the nearest multiple of 5:

=FLOOR(A1,5) // round down to nearest 5

Example #2 - round pricing down to end with .99

FLOOR can be used to set pricing after currency conversion, discounts, etc. For example, the formula below will round a number in A1 down to the next whole dollar, then subtract 1 cent, to return a price like $2.99, $5.99, $49.99, etc.

=FLOOR(A1,1)-0.01

You can round pricing up to end in .99 with a similar formula based on the CEILING function:

=CEILING(A1,1)-0.01

Example #3 - round time down to nearest 15 minutes

FLOOR understands time formats, and can be used to round time down to a given multiple. For example, to round a time in A1 down to the previous 15 minute unit, you can use FLOOR like this:

=FLOOR(A1,"0:15") // round time down to nearest 15 min

Other rounding functions in Excel

To round normally, use the ROUND function.
To round to the nearest multiple, use the MROUND function.
To round down to the nearest specified place, use the ROUNDDOWN function.
To round down to the nearest specified multiple, use the FLOOR function.
To round up to the nearest specified place, use the ROUNDUP function.
To round up to the nearest specified multiple, use the CEILING function.
To round down and return an integer only, use the INT function.
To truncate decimal places, use the TRUNC function.

Notes

FLOOR works like the MROUND function, but FLOOR always rounds down.
If a number is already an exact multiple of significance, no rounding occurs.
FLOOR rounds positive numbers down toward zero.
FLOOR rounds negative numbers down away from zero.
For more control with negative numbers, see the FLOOR.MATH function.

Related functions

Excel MROUND Function

The Excel MROUND function returns a number rounded to a given multiple. MROUND will round a number up or down, depending on the nearest multiple.

Excel CEILING Function

The Excel CEILING function rounds a given number up to the nearest specified multiple. CEILING works like the MROUND function, but CEILING always rounds up.

Excel ROUND Function

The Excel ROUND function returns a number rounded to a given number of digits. The ROUND function can round to the right or left of the decimal point.

Excel ROUNDDOWN Function

The Excel ROUNDDOWN function returns a number rounded down to a given number of places. Unlike standard rounding, where only numbers less than 5 are rounded down, ROUNDDOWN rounds all numbers down.

Excel ROUNDUP Function

The Excel ROUNDUP function returns a number rounded up to a given number of decimal places. Unlike standard rounding, where numbers less than 5 are rounded down, ROUNDUP rounds all numbers up.

Excel FLOOR Function

The Excel FLOOR function rounds a given number down to the nearest specified multiple. FLOOR works like the MROUND function, but FLOOR always rounds down.

Excel INT Function

The Excel INT function returns the integer part of a decimal number by rounding down to the integer. Note the INT function rounds down, so negative numbers become more negative. For example, while INT(10.8) returns 10, INT(-10.8) returns...

Excel TRUNC Function

The Excel TRUNC function returns a truncated number based on an (optional) number of digits. For example, TRUNC(4.9) will return 4, and TRUNC(-3.5) will return -3. The TRUNC function does no rounding, it simply truncates as specified.