Vehicle Economics

Auto Loan Early Payoff Calculator

Plan an early payoff with a recurring extra payment, an optional lump sum, or both.

Why this comes up

A tax refund, a bonus, or just a habit of rounding up your payment, extra cash toward a car loan is one of the easiest ways to cut interest, but it's hard to know how much it actually moves the needle without running the numbers. This engine combines a recurring extra and a one-time lump sum in the same plan, so you can see the real payoff date instead of guessing.

How we calculated this

We run your loan's amortization schedule twice: once at your stated payment alone, once with your extra monthly amount and lump sum applied in the month you specify. The difference in payoff month and total interest between the two runs is what you see below.

Worked example, using this page's own defaults ($15,000 balance, 6% APR, $400/month, 42 months remaining, no extras): the loan pays off in month 42 as scheduled. Add a $100/mo extra and the payoff date pulls forward meaningfully, try it above.

What this means

  • A dollar applied early saves more interest than the same dollar applied late, because it stops accruing interest sooner. An early lump sum beats the same cash spread out as a later recurring extra.
  • If your payment doesn't even cover the current month's interest, the loan can't amortize at all, this engine flags that instead of showing a false payoff date.
  • Before committing cash to extra payments, compare against Cash vs Finance a Car style tradeoffs: guaranteed interest savings against what that same cash could otherwise earn or cover.

Limitations

This does not know your lender's specific prepayment rules, some contracts have restrictions or fees on early payoff. Confirm with your loan servicer before committing to a plan. See Methodology.

Sensitivity: extra monthly payment

Drag to see the payoff month and interest saved change live, without touching the form above.

Methodology

This engine is built on Vehicle Economics' fixed-rate amortization model: the standard loan-payment formula run out as a full month-by-month schedule. See Methodology for the full detail.

Next decision