How this calculation works
Back-solve the approximate annual interest rate from loan amount, instalment, and repayment count. The result is calculated locally in your browser from the visible inputs, and the method below remains available for checking.
Worked example
A ₹3 lakh principal repaid through 36 payments of about ₹10,035 back-solves the implied annual rate.
Assumptions and limits
- Inputs use the units shown beside each field.
- Intermediate values retain precision; displayed values are rounded for readability.
Questions people ask
How does the Interest Rate Calculator work?
It applies this displayed method: The periodic loan equation is solved iteratively for the rate, then annualised as nominal and effective rates. Values stay in your browser and are not submitted to a server.
What should I check before using the Interest rate result?
Inputs use the units shown beside each field. Intermediate values retain precision; displayed values are rounded for readability. This is an estimate, not a lender quote. Rates, fees, rounding and repayment rules vary by agreement.
Does this Interest rate calculator save my information?
No. Calculation inputs are processed on this device. Sharing creates a URL only when you choose the share action.