Interest Rate Calculator
Already know your loan amount, payment, and term, but not the interest rate? This calculator solves for it.
Implied annual interest rate
10.18%
What Your Result Means
The implied annual interest rate is the rate that, combined with your loan amount and term, would produce exactly the monthly payment you entered. It's the reverse of a typical loan calculation.
How It Is Calculated
Calqora uses a numerical search (bisection method) to test interest rates until it finds the one where the standard loan payment formula produces your entered monthly payment.
Worked Example
A $15,000 loan paid off with $320/month over 5 years implies an annual interest rate of roughly 7.4%.
Important Assumptions
- Assumes a standard fixed-rate, fully amortizing loan.
Frequently Asked Questions
- Why would I need to find the interest rate?
- This is useful when you know your payment and terms from a contract or offer, but the interest rate wasn't clearly stated, or you want to verify it.
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Methodology
This calculator uses a bisection numerical method to solve for the rate. See our methodology page for details.
This calculator provides estimates for educational purposes only. Actual rates, taxes, insurance, fees, and lender terms may differ. It does not constitute financial advice - consult a qualified financial professional before making financial decisions.