Effective Interest Rate Calculator
Convert a nominal annual rate into an effective annual rate for different compounding frequencies
Effective annual rate
How we calculated it
About the Effective Interest Rate Calculator
Effective interest rate shows the annual rate after accounting for compounding within the year. It makes nominal rates with different compounding frequencies easier to compare.
The effective annual rate is usually slightly higher than the nominal rate when interest compounds more than once per year.
How to Use the Effective Interest Rate Calculator
- Enter the nominal annual interest rate.
- Enter the number of compounding periods per year.
- Calculate the effective annual rate.
- Use the effective rate when comparing products that quote the same nominal rate with different compounding frequencies.
How the Calculation Works
Effective annual rate EAR = (1 + r/n)^n − 1, where r is the nominal annual rate and n is the number of compounding periods per year.
For continuous compounding, the corresponding limit is e^r − 1.
Worked example
Effective Interest Rate Calculator Worked Example
12% nominal rate compounded monthly
EAR = (1+0.12/12)^12−1 = 1.01^12−1 ≈ 0.1268, or about 12.68%.
Result guide
Understanding Your Effective Interest Rate Calculator Result
The effective rate reflects the actual annual growth caused by the stated compounding frequency, assuming the nominal rate and compounding pattern remain constant.
Before you rely on the answer
Assumptions and Limitations
- The nominal rate is stated on an annual basis.
- Compounding frequency is entered correctly.
- Fees and taxes are excluded.
Practical tip
Using This Result in Practice
When comparing deposit or borrowing products, make sure you are comparing like with like: nominal rate to nominal rate or effective rate to effective rate. For borrowing, an effective rate derived only from compounding still does not include origination fees or other charges. Use APR or total-cost analysis when fees are material to the decision.
Related calculations
Useful Calculations to Continue With
If you want to see the dollar effect of compounding on a balance, use the Compound Interest Calculator.
If borrowing fees as well as interest matter, use the APR Calculator rather than effective rate alone.
Common questions
Effective Interest Rate Calculator FAQ
Why is effective rate higher than nominal rate?
Because interest is added during the year and later periods can earn or incur interest on that interest.
Does more frequent compounding always increase EAR?
For the same positive nominal rate, yes, though the increments get smaller as frequency rises.
Is EAR the same as APR?
Not necessarily. APR can include borrowing fees and may use different disclosure conventions.