# Effect

The Effect function returns the effective annual interest rate.

Lending institutions advertise the nominal rate of their loans. Theย nominal interest rate does not take into account the effect of compounding. The effective interest rate takes the compounding period into account, and it is a more accurate measure of interest charges.

## Syntax

``````Effect(nominal_rate, num_per_year)
``````

Function arguments:

nominal_rateThe nominal interest rate as a decimal (for example, for 7%, input `0.07`).
num_per_yearThe number of compounding periods per year.

## Notes

The general formula for the Effect function is:

## Examples

``````Effect(.0678, 12)
``````

The effective annual interest rate for an effective rate of 6.78%, paid 12 times a year (monthly). This example returns 7.00%.

``````Nominal(0.677, 26)
``````

The nominal annual interest rate for an effective rate of 6.77%, paid 26 times a year (bi-weekly). This example returns 7.00%.

``````Effect(0.1, [Number of Periods]
``````

Explore how the the effective annual interest rate changes when the nominal interest rate is 10% applies to investments with a different number of periods.

Related resources