Auto Refinance Calculator — Old vs New APR

Todd Mitchell (photo)
By Todd Mitchell
On: Saturday, June 13, 2026 10:02 AM
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Auto Refinance Savings Calculator

Compare your current auto loan APR against a refinance rate and see exactly how much you’ll save over the remaining life of the loan. Refinancing is free, takes 10 minutes online, and often saves $50–150 per month on cars under 5 years old.

Refinance Auto Loan

Compare your current loan with a refinance offer including fees.

Old payment
New payment
Total savings

How It Works

Refinancing replaces your existing loan with a new one at a lower APR. The new lender pays off the old lender directly. Your monthly payment drops, the total interest paid drops, and the loan term can stay the same or shorten.

Formula: Monthly savings = Old payment − New payment. Lifetime savings = (Old payment × remaining months) − (New payment × new months) − fees.

How to Use This Calculator

  1. Find your current APR and the remaining balance (call your lender or check the most recent statement).
  2. Get pre-approved at 2–3 lenders — credit unions and online lenders like LightStream and Capital One are the best starting point.
  3. Enter old APR, remaining balance, remaining months, and the new offered APR.
  4. The calculator returns monthly savings and total lifetime savings.
  5. Accept the offer with the lowest APR — don’t pay any “loan fees” or “doc fees” higher than $50.

Worked Example

Example: Original 72-month loan at 8.5% APR, 48 months remaining, $22 000 balance. Refinance to 6.0% APR over same 48 months. Old payment $623, new payment $593 = $30/mo savings, $1 440 lifetime.

Reference Table

Decision matrix for auto loan refinancing. Most lenders require at least 6 months on the original loan before refinancing.

Scenario Worth refinancing?
APR drop ≥ 2 percentage points Yes — strong savings
APR drop 1–2 points Maybe — check fees and remaining term
APR drop under 1 point Probably not — savings barely cover effort
Less than 12 months remaining No — too little interest left to save
Credit score improved 50+ pts Yes — even at same listed APR, your offer beats current
Underwater on the loan (LTV>100%) No — most lenders won’t refinance
Want to extend term Possible, but raises total interest

Frequently Asked Questions

Are there fees to refinance an auto loan?

Usually no. Most US auto refinance lenders charge $0 — no origination, no application, no doc fees. If a lender wants more than $50, find a different one.

Does refinancing hurt my credit?

Mildly. Each application triggers a hard pull (5–10 point drop, recovers in 3–4 months). Shop multiple lenders within 14 days and the credit bureaus count them as one inquiry.

Can I refinance if I’m underwater on the loan?

Rarely. Most lenders cap loan-to-value (LTV) at 110–130%. If you owe more than that, you’ll need to pay down the difference first. Some online lenders go to 135% LTV — shop around.

Should I refinance to a longer term to lower my payment?

Only if cash flow is critical. Extending the term raises total interest paid. A better path: refinance to a shorter term at the lower APR and keep the same payment — you pay off the loan sooner.

How long does refinancing take?

Online: 10 minutes to apply, 1–3 business days to fund. The new lender pays off your old loan directly. Your old account closes automatically.