Is there a formula to calculate the interest on a car loan?

Is there a formula that I can use to calculate the interest on my car loan by hand? I know there are calculators online, but I would rather do the math myself if that’s possible.

Liz Jenson · Updated on
Reviewed by Shannon Martin, Licensed Insurance Agent.
Yes, there is a formula that you can use to calculate the interest that you’ll pay on your car loan. You can ask your lender for the monthly payment amount, or you can use this equation to calculate it yourself: Monthly Payment = loan principal x (monthly interest rate (1 + monthly interest rate) months in loan term) / ((1 + monthly interest rate) months in loan term - 1)
If you don’t know the monthly interest rate, you can simply divide the APR by 12.
Once you know your monthly payment amount, you can use this equation to find the total interest: (The monthly payment amount x the loan term in months) - principal = total interest
Calculating the total interest on a car loan can be complicated, but it’s easy to find the best car insurance rates when you use the
app. Just download the app and answer some quick questions to see your policy options in a comprehensive list. When you find a quote you like, Jerry can help you cancel your old policy and sign up. The average user saves $879 per year.
View full answer 
Jerry partners with more than 50 insurance companies, but our content is independently researched, written, and fact-checked by our team of editors and agents. We aren’t paid for reviews or other content.

Join 4M+ members in lowering their car insurance

Easiest way to compare and buy car insurance

No long forms
No spam or unwanted phone calls
Quotes from top insurance companies
Find insurance savings