Summary

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.

Purpose 

Round down to given number of digits

Return value 

A rounded number.

Syntax

=ROUNDDOWN(number,num_digits)
  • number - The number to round down.
  • num_digits - The place at which number should be rounded.

How to use 

The ROUNDDOWN function rounds numbers down. Unlike standard rounding, where only numbers less than 5 are rounded down, ROUNDDOWN rounds all numbers down. For example:

=ROUNDDOWN(3.9,0) // returns 3

ROUNDDOWN takes two arguments, number and num_digits. Number is the number to be rounded, and num_digits is the place at which number should be rounded. When num_digits is greater than zero, the ROUNDDOWN function rounds on the right side of the decimal point. When num_digits is less or equal to zero, the ROUNDDOWN function rounds on the left side of the decimal point. Use zero (0) for num_digits to round to the nearest integer. The table below summarizes this behavior:

Digits Behavior
>0 Round down to nearest .1, .01, .001, etc.
<0 Round down to nearest 10, 100, 1000, etc.
=0 Round down to nearest 1

Round to right of decimal

To round down values to the right of the decimal point, use a positive number for digits:  

=ROUNDDOWN(A1,1) // Round down to 1 decimal place
=ROUNDDOWN(A1,2) // Round down to 2 decimal places
=ROUNDDOWN(A1,3) // Round down to 3 decimal places
=ROUNDDOWN(A1,4) // Round down to 4 decimal places

Round to left of decimal

To round down values to the left of the decimal point, use zero or a negative number for digits:  

=ROUNDDOWN(A1,0) // Round down to nearest 1
=ROUNDDOWN(A1,-1) // Round down to nearest 10
=ROUNDDOWN(A1,-2) // Round down to nearest 100
=ROUNDDOWN(A1,-3) // Round down to nearest 1000
=ROUNDDOWN(A1,-4) // Round down to nearest 10000

Nesting inside ROUNDDOWN

Other operations and functions can be nested inside ROUNDOWN. For example, to round down the result of A1 divided by B1, you can use a formula like this:

=ROUNDDOWN(A1/B1,0) // round down result to nearest integer

Other rounding functions

Excel provides a number of of rounding functions, each with a different behavior:

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Dave Bruns

Hi - I'm Dave Bruns, and I run Exceljet with my wife, Lisa. Our goal is to help you work faster in Excel. We create short videos, and clear examples of formulas, functions, pivot tables, conditional formatting, and charts.