The ROUNDDOWN function is used to decrease a value by a specified number of decimals or digits. It keeps the same rounding numbers, changes the value of the data in the cell and rounds down to zero.
Remark. The information in this article applies to Excel 2019, Excel 2016, Excel 2013, Excel 2010, Excel 2019 for Mac, Excel 2016 for Mac, Excel for Mac 2011, and Excel Online.
 ROUNDDOWN Function Syntax and Arguments
 Enter the ROUNDDOWN function
ROUNDDOWN Function Syntax and Arguments
Syntax for the ROUNDDOWN function:
= ROUND(Number, Number_digits)
Arguments for the function:
Number – (mandatory) value to round. This argument can contain the actual data to be rounded, or it can be a cell reference for the location of the data on the worksheet.
Number_digits – (mandatory) the number of digits to which the argument is rounded number †

as argument Number_digits set to 0, the function rounds the value to the nearest integer.

as argument Number_digits set to 1, the function leaves only one digit to the right of the decimal point and rounds to the next number.

as argument Number_digits is negative, all decimal places are removed and the function rounds that number of digits to the left of the decimal point to zero. For example, if the value of the argument Number_digits set to 2, the function removes all digits to the right of the decimal point and rounds the first and second digits to the left of the decimal point to the nearest 100, as shown in the example on line 6 in the image above.
The image above shows examples and explains some of the results returned by Excel’s ROUNDDOWN function for the data in column A of the worksheet. The results in column C depend on the value of the argument Number_digits †
The instructions below describe the steps taken to reduce the number in cell A2 in the image above to two decimal places using the ROUNDDOWN function. Because the function always rounds, the rounding figure does not change.
Enter the ROUNDDOWN function
Input options for a function and its arguments include:

Full function input: =ROUND(A2,2) in cell C3 on the worksheet;

Select a function and arguments using the function dialog box.
Using a dialog box makes it easier to enter function arguments. When using this method, there is no need to enter commas between each of the function arguments, as it should be when entering a function in a cell, in this case between A2 And 2.
The steps below show how to access the ROUNDDOWN function using the dialog box in Excel 2019, Excel 2016, Excel 2013, Excel 2010, and Excel for Mac.

Select cell C3 to make it active. The results of the ROUNDDOWN function are shown here.

Select formulas †

Select Mathematics and Triggers to open the dropdown list of functions.

Select ROUND DOWN in the list to open the function’s dialog box.

In the dialog box, select the line Number †

Select cell A2 on the worksheet to enter that cell reference in the dialog box as the location of the number to be rounded.

Select line Number_digits †

Enter 2 to enter the number. to lower A2 from five to two decimal places.

Select Okay to close the dialog box and return to the worksheet.

The answer 567.96 appears in cell C3.
When cell C2 is selected, the entire function =ROUNDDOWN(A2,2) appears in the formula bar above the worksheet.
Excel Online does not have a tab with formulas. Use the formula bar to use the ROUNDDOWN function in Excel Online.

Select cell C3 to make it active. The results of the ROUNDDOWN function are shown here.

Press the button Insert function next to the formula bar.

Select Mathematics and Triggers in the “Select Category” dropdown list.

Select ROUND DOWN in the Select Function list.

Select Okay †

Select cell A2 to select it as the Number argument.

Enter 2 to enter the number. to lower A2 from five to two decimal places.

Click Enter †
When cell C2 is selected, full function = ROUNDDOWN(A2,2) appears in the formula bar above the worksheet.