Find out the real rate on a loan. This free interest rate calculator works backward from your loan amount, monthly payment and term to the APR you’re actually paying.
Results update automatically as you type. Reverse-engineers the rate from your loan, payment and term.
Use this free interest rate calculator to find the interest rate on a loan when you know the amount, the monthly payment and the term. Enter the three and it works out the APR for you.
An interest rate calculator reverse-engineers the rate hidden in a loan. Give it the loan amount, monthly payment and term, and it solves for the annual interest rate (APR), along with the monthly rate, total interest and total paid. It’s the answer to “what rate am I actually being charged?”
The loan payment formula can’t be rearranged to isolate the rate directly, so this calculator solves it numerically. You don’t need to do any math — just enter your figures. For a $20,000 loan repaid at $400 a month over 5 years, the implied rate is about 7.4% APR, with $4,000 in total interest.
This tool finds the annualized interest rate implied by your payments. A lender’s quoted APR may be slightly higher because it can include certain fees. Use this calculator to check whether a quoted rate matches the payments you’re actually being asked to make.
| Term | What it means |
|---|---|
| Interest rate | The cost of borrowing, as a percentage of the balance. |
| APR | The annual rate, sometimes including fees. |
| Monthly rate | The annual rate divided by 12, used in payments. |
| Term | The length of the loan. |
Enter the loan amount, your monthly payment and the term. The calculator solves the loan equation for the rate, since it can't be rearranged by hand. A $20,000 loan paid at $400 a month over 5 years works out to about 7.4% APR.
An interest calculator works out how much interest you'll earn or pay from a known rate. This interest rate calculator does the reverse — it finds the rate when you already know the loan, payment and term.
APR is the annual percentage rate — the yearly cost of borrowing. A lender's quoted APR can include certain fees, so it may be slightly higher than the rate implied by payments alone.
This tool derives the rate purely from your payments. If a lender's APR includes origination or other fees, their figure can be a touch higher than the payment-implied rate shown here.
Yes — any fixed-rate, fixed-payment loan such as a personal loan, auto loan or mortgage. Just make sure the payment and term reflect principal and interest.
Yes, this interest rate calculator is completely free, needs no sign-up, and gives instant results directly in your browser.