EFFECT function
Returns the effective annual interest rate, given the nominal annual interest rate and the number of compounding periods per year.
Syntax
EFFECT(nominal_rate,npery)
Nominal_rate is the nominal interest rate.
Npery is the number of compounding periods per year.
Remarks

Npery is truncated to an integer.

If either argument is nonnumeric, EFFECT returns the #VALUE! error value.

If nominal_rate ≤ 0 or if npery < 1, EFFECT returns the #NUM! error value.

EFFECT is calculated as follows:
Example
The example may be easier to understand if you copy it to a blank worksheet.
How to copy an example

Create a blank workbook or worksheet.

Select the example in the Help topic.
Note Do not select the row or column headers.
Selecting an example from Help

Press CTRL+C.

In the worksheet, select cell A1, and press CTRL+V.

To switch between viewing the results and viewing the formulas that return the results, press CTRL+` (grave accent), or on the Formulas tab, in the Formula Auditing group, click the Show Formulas button.

