The Excel FLOOR.MATH function rounds a number down to the nearest integer or multiple, with an optional mode argument that controls how negative numbers behave.
Syntax
| Argument | Description | |
|---|---|---|
number | Required | The value you want to round down. |
significance | Optional | The multiple to round to. Defaults to 1 (the previous integer). |
mode | Optional | Controls direction for negative numbers. Omitted/0 rounds away from zero (down); any non-zero value rounds toward zero. |
How to use it
FLOOR.MATH improves on classic FLOOR: significance is optional (defaults to 1) and signs never cause an error.
For positives it always rounds down. For negatives the default rounds away from zero (genuinely down), while a non-zero mode rounds toward zero instead.
Default mode: with mode omitted, =FLOOR.MATH(-5.5) gives -6 (down, away from zero). Add a non-zero mode — =FLOOR.MATH(-5.5, 1, 1) — to get -5 instead.
Try it: interactive demo
Pick a FLOOR.MATH example to see the formula and its result.
Practice workbook
Frequently asked questions
What does the mode argument do?
How is FLOOR.MATH different from FLOOR?
significance optional (defaults to 1), never errors on mixed signs, and adds a mode argument for negatives.Why does FLOOR.MATH(-5.5) give -6 instead of -5?
=FLOOR.MATH(-5.5, 1, 1) = -5.Is FLOOR.MATH the same as INT for negatives?
=FLOOR.MATH(-5.5) and =INT(-5.5) return -6, rounding toward negative infinity.Master functions like this in one day
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