The Excel MOD function returns the remainder of a division between two supplied numbers.
The syntax of the function is:
where the arguments are as follows:
number    The number to be divided. 
divisor    The value that the number argument is divided by. 
The spreadsheet below shows four simple examples of the Excel Mod function.
Formulas:
 Results:

Further details of the Excel Mod function are provided on the Microsoft Office website.
If you get an error from the Excel Mod function this is likely to be one of the following:
#DIV/0!    Occurs if the supplied divisor argument is zero. 
#VALUE!    Occurs if any of the supplied arguments are nonnumeric. 