The Excel Nominal function returns the nominal interest rate for a given effective interest rate and number of compounding periods per year.
The syntax of the function is:
where the arguments are as follows:
effect_rate    The effective interest rate (a numerical value, between 0 and 1). 
npery    The number of compounding periods per year (must be a positive integer). 
In the following spreadsheet, the Excel Nominal function in used to calculate the nominal interest rate of three loans with different terms.
Formulas:

Results:

If the result from your Nominal function is displayed as a decimal, or shows 0%, both of these problems are likely to be due to the formatting of the cell containing the function.
Therefore the problem can be fixed by formatting the cell as a percentage, with decimal places.
To do this:
Open up the 'Format Cells' dialog box using any one of the following methods:
Within the 'Format Cells' dialog box:
Select Percentage from the Category list on the left side of the dialog box.
This will cause further options to appear on the right hand side of the control box, which allow you to select the number of decimal places that you want to be displayed (see rightabove).Further details and examples of the Excel Nominal function are provided on the Microsoft Office website.
If you get an error from the Excel Nominal function this is likely to be one of the following:
#NUM!   
Occurs if either:

#VALUE!    Occurs if one or both of the supplied arguments are nonnumeric. 