Auto Loan Early Payoff Calculator
Making extra principal payments on your auto loan reduces the outstanding balance faster, which reduces the interest that accrues each month. Enter your current loan balance, APR, remaining term, regular payment, and any extra monthly payment or one-time lump sum. The calculator runs both scenarios: standard amortization versus amortization with extra payments, and shows the interest saved and months eliminated from your loan term.
Extra payment interest savings formula
Standard: simulate n months with regular payment P. Extra: simulate with P + extra each month. Interest saved = total standard interest - total extra interest.
Each month: interest = balance * (APR/12/100); balance = balance + interest - payment. Repeat until balance reaches zero. The difference in total interest between the two scenarios is your savings.
How much can you save?
On a $15,000 auto loan at 7.5% APR with 48 months remaining, adding $100 per month extra typically saves around $500 to $700 in interest and cuts 6 to 9 months from the loan. The savings are most significant when the extra payment is applied early in the remaining term, when the balance is still high. Confirm with your lender that extra payments are applied to principal, not future payments.
Frequently asked questions
How does paying extra on an auto loan save money?
Extra payments reduce the outstanding principal balance. Because interest accrues on the balance, a lower balance means less interest each month. The savings compound: less interest next month leaves more room for further principal reduction.
Are there prepayment penalties on auto loans?
Most US auto loans do not have prepayment penalties. However, some simple-interest contracts and some dealer-arranged financing may include early payoff penalties. Check your loan agreement before making extra payments.
Should I pay off my auto loan early or invest?
If your auto loan APR exceeds your expected after-tax investment return, paying off the loan first is mathematically better. Auto loan rates vary from 5% to 15% or more depending on credit score and term, while average stock market returns over 10-year periods have historically been around 7% to 10% annually.
Does paying off a car loan early hurt my credit?
Paying off a loan closes the account, which can slightly reduce the average age of accounts and the mix of credit types. However, the reduction in debt and improvement in payment history generally outweigh these minor effects for most borrowers.
What is the difference between extra monthly payments and a lump sum?
A lump sum reduces the balance immediately, saving the most interest right away. Extra monthly payments provide a smaller but ongoing reduction. Both are effective; a lump sum typically saves slightly more total interest than spread out over time if the amounts are equivalent.
Official sources
- CFPB: Auto Loans.
- Federal Reserve Consumer Credit G.19: Consumer Credit Release.
Reviewed by the CalculatorHub team, edited by James Graham, 15 June 2026. See our methodology.