Car Loan Payoff Calculator

How Extra Payments Shorten a Car Loan

Every car loan payment is split between interest (the cost of borrowing) and principal (what actually reduces your balance). Early in the loan, a bigger share of each payment goes to interest; as the balance shrinks, more of each payment chips away at principal instead. Any extra amount you add on top of your regular payment goes entirely toward principal, which does two things at once: it shrinks the balance interest is calculated on for every remaining month, and it moves up the date you're done paying entirely.

Because of this compounding effect, extra payments made earlier in the loan save more than the same extra amount made later — but adding even a modest amount consistently, at any point, still meaningfully cuts both your payoff time and your total interest cost.

How to Use This Calculator

Enter your current loan balance, your interest rate, and how many months are left on your original loan term. Then enter how much extra you plan to pay each month on top of your regular payment — the calculator works out your standard monthly payment automatically from the first three fields.

How We Calculate It

We first work out your standard monthly payment using the standard loan amortization formula, based on your balance, rate, and remaining term. That gives us your baseline: what you'd pay in total interest if you stuck to that fixed payment for the full remaining term. We then simulate your loan month by month with your extra payment added on top, recalculating the interest and principal split each month until the balance reaches zero. Comparing the two scenarios gives you the months saved and interest saved shown above.

A Few Notes

This calculator assumes a fixed interest rate and that you apply the same extra amount every month without missing any payments — real budgets and loan terms can vary, so treat the result as a close estimate rather than a figure your lender will match to the penny. Also worth checking before you commit to a payoff strategy: some auto loans charge a prepayment penalty for paying off early, so confirm your loan agreement doesn't include one before sending extra payments.