ROUNDDOWN
TheROUNDDOWN
formula rounds a number down to a specified number of decimal places. It is commonly used in financial calculations, such as calculating the total cost of a purchase including tax. The formula takes a required value
parameter and an optional places
parameter specifying the number of decimal places to round to.
 How to use
ROUNDDOWN
formula?  Examples of using
ROUNDDOWN
formula ROUNDDOWN
formula not working? Similar formulas to
ROUNDDOWN
Usage
Use the ROUNDDOWN
formula with the syntax shown below, it has 1 required parameter and 1 optional parameter:
 value (required):
The number to be rounded down.  places (optional):
The number of decimal places to round to. If omitted, the default value is 0.
Examples
Here are a few example use cases that explain how to use theROUNDDOWN
formula in Google Sheets.
Rounding down to the nearest whole number
When calculating the quantity of items needed for a project, you may want to round down to the nearest whole number to ensure that you don't overestimate the amount needed. The ROUNDDOWN
formula can be used to achieve this.
Calculating sales tax
When calculating sales tax on a purchase, you may want to round down the total cost to the nearest cent. The ROUNDDOWN
formula can be used to achieve this.
Calculating depreciation
When calculating depreciation of an asset, you may want to round down the calculated value to the nearest dollar. The ROUNDDOWN
formula can be used to achieve this.
Common Mistakes
ROUNDDOWN
not working? Here are some common mistakes people make when using the ROUNDDOWN
Google Sheets Formula:
Missing value argument
If you forget to provide the value argument, the function will return an error. Make sure to include the value you want to round down.
Incorrect number of arguments
If you provide more or less than two arguments, the function will return an error. Doublecheck that you have included both the value and the number of decimal places.
Incorrect data type
If you provide a value that is not a number, the function will return an error. Make sure to only use numeric values as the first argument.
Negative number of decimal places
If you provide a negative number of decimal places, the function will return an error. Make sure to only use positive values for the second argument.
Incorrect rounding direction
Remember that ROUNDDOWN always rounds down, regardless of the value. If you need to round up, use the ROUNDUP function instead.
Related Formulas
The following functions are similar to ROUNDDOWN
or are often used with it in a formula:

ROUND
The
ROUND
formula rounds a number to a specified number of decimal places. It is commonly used to simplify large numbers or to make a number more readable. The formula can round both positive and negative numbers. If theplaces
parameter is not specified, the formula rounds to the nearest integer. 
CEILING
The
CEILING
function returns a number rounded up to the nearest multiple of a specified factor. It is commonly used to round up prices to the nearest dollar or to adjust numbers to fit into specific increments. 
FLOOR
The FLOOR formula rounds a given number down to the nearest multiple of a specified factor. It is commonly used when dealing with financial data or when working with time values. The function takes a value and an optional factor as arguments and returns the rounded down value.

MROUND
The
MROUND
function rounds a number to the nearest multiple of a specified factor. It is commonly used when dealing with financial data, such as currency or interest rate calculations.
Learn More
You can learn more about the ROUNDDOWN
Google Sheets function on Google Support.