Interest rate calculator
This interest rate calculator works backwards from your payment: enter the amount borrowed, the monthly payment and the term to find the rate.
Why the quoted payment hides the rate
A payment quote can hide a high rate behind a long term. For example, $25,000 financed over 84 months at 6% is $365.21, and the same payment is available at a much higher rate over a shorter term only if you ask. Work out the APR from any quote and compare it with your pre-approval.
Frequently asked questions
How do you work out the interest rate from a payment?
There is no closed-form formula, so the calculator searches for the rate at which the payment exactly repays the amount over the term. The result is the rate that accrues monthly on the balance, the same as an APR on a standard installment loan without extra fees.
Why is my rate different from the dealer’s quote?
Fees, add-ons and rounding can raise the effective cost. If the rate you get here is higher than the quoted rate, ask what was added to the amount financed.
Related calculators
Estimates from standard loan formulas, not a loan offer or financial advice. Example rates are assumptions: use your own quote.