Vehicle EconomicsAuto Refinance Break-Even Calculator
How many months until a refinance actually recovers its fees, balance-adjusted.
Why this comes up
Refinancing usually comes with fees, and a payment-only comparison can quietly mislead you: a lower payment can still leave you with a larger remaining balance at the point you actually sell or trade, which erases the apparent win. This engine finds the month the refinance genuinely pays for itself, balance included, not just payment-versus-payment.
How we calculated this
At each month, we compare cumulative cash paid plus remaining balance owed on both the existing loan and the proposed refinance (with its fee, cash or financed). The month where the proposed path first costs less overall is the break-even.
Worked example, using this page's own defaults ($18,000 at 9% moving to 5% APR with a $500 cash fee): recovery happens well within the 48-month horizon, run the calculator above for your own figures.
What this means
- If you plan to sell or trade before the break-even month, the refinance likely doesn't pay off for you specifically, even if the rate is genuinely better.
- Financing the fee instead of paying cash changes the shape of this calculation, not just the sign, run both toggles to see the difference.
- Once you know the break-even, use Auto Loan Refinance Calculator for the full payment and lifetime-cost comparison.
Limitations
This does not model credit-score impact, lender underwriting risk, or a prepayment penalty on your existing loan, if one exists, add it to the fee figure. See Methodology.
Methodology
This engine combines Vehicle Economics' fixed-rate amortization model (the standard loan-payment formula run out as a full month-by-month schedule) and break-even search model (a closed-form solve where one exists, otherwise a bounded search over a stated plausible range). See Methodology for the full detail.