Auto Loan Early Payoff Calculator
Short answer: paying extra on an auto loan saves you money because interest is charged on your remaining balance each month — cut the balance faster and you cut the interest. Enter your loan below to see exactly how much interest you'd save and how many months you'd shave off.
How this calculator works
The tool builds a full month-by-month amortization schedule for your loan. First it finds your standard payment using the loan formula M = P · r / (1 − (1 + r)−n), where P is the balance, r is the monthly rate (APR ÷ 12), and n is the number of months. Then it runs two schedules in parallel: one paying only the minimum, and one adding your extra monthly amount plus any lump sum. Each month it charges interest on the current balance, subtracts your payment, and repeats until the balance hits zero. The difference in total interest and number of months is what you save. Everything runs in your browser; nothing you type is sent anywhere.
Why extra payments work on a car loan
Nearly all U.S. auto loans use simple interest, meaning the finance charge each month equals your balance times the monthly rate. Early in the loan the balance is large, so most of your payment goes to interest and little to principal. When you add an extra payment, that full amount goes straight to principal, permanently removing it from every future interest calculation. The effect compounds: a smaller balance this month means less interest next month, which means more of your regular payment attacks principal, and so on. That is why even a modest $50–$100 a month can erase a year or more from a typical loan.
| Original term | Interest (minimum) | Interest (with +$100) | Time cut |
|---|---|---|---|
| 48 months | ~$4,500 | ~$3,820 | ~7 months |
| 60 months | ~$5,660 | ~$4,630 | ~10 months |
| 72 months | ~$6,860 | ~$5,380 | ~14 months |
Figures are illustrative; use the calculator for numbers matched to your exact loan.
Three ways to pay extra
You can round every payment up to the next $50 or $100, add a fixed extra amount automatically, or throw a single lump sum (a tax refund or bonus) at the principal. The earlier in the loan you do it, the more you save, because the removed principal avoids the most months of interest. Read our step-by-step payoff guide for the mechanics, or see extra payments vs. lump sum vs. refinancing to choose the right strategy.
Frequently asked questions
Does paying my car loan off early save money?
Yes. Auto loans are simple-interest, so interest accrues on the outstanding balance each month. Every extra dollar of principal you pay reduces the balance that future interest is charged on, which lowers total interest and shortens the term. The calculator above shows the exact dollar amount for your loan.
Is it better to make extra monthly payments or one lump sum?
Both help, but timing matters. A lump sum paid early in the loan removes principal sooner, so it usually saves slightly more interest than spreading the same money across later monthly payments. The tool lets you compare the two directly.
Will extra payments lower my monthly bill?
No. On a standard auto loan, extra payments shorten the term but the required monthly payment stays the same until the loan is gone. If you want a lower monthly payment instead, that requires refinancing or recasting, which most auto lenders do not offer.
Are there prepayment penalties on auto loans?
Most U.S. auto loans have no prepayment penalty, but a minority use precomputed interest or charge a fee. Check your contract for the words 'precomputed' or 'prepayment penalty' before sending large extra payments.
How do I make sure extra money goes to principal?
Tell your lender in writing (or use the 'principal only' option in their app) that additional amounts should be applied to principal, not pre-paid toward next month's bill. Otherwise some servicers simply advance your due date and you save nothing.