Should I finance the refi fees?

This model assumes fees are paid upfront. Financing them would raise total interest slightly; add them to the balance if you want to approximate that.

What if I extend the term?

Payment drops but total interest can rise. Check the interest saved line—if negative, you’re paying more overall.

Do taxes and insurance change?

No, this is P&I only. Your insurance/taxes don’t change because of the refinance.

Negative equity rolled in?

Enter the true payoff as current balance to reflect any rolled-in negative equity. This model doesn’t separately track it.

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Auto Refinance Calculator

Compare your current auto loan to a refinance option to see payment change, interest savings, and breakeven after refi fees.

Results

Current monthly payment (P&I): $446
Balance today: $16,294
Interest remaining (current): $2,441
New monthly payment (P&I): $311
Interest over new term: $2,380
New term length (months): 60.00
Refi fees added: $350
Monthly payment change: $135
Breakeven months on fees: 2.60
Interest saved vs current: $61

How to use this calculator

Enter your current balance, rate, original term, and months elapsed.
Enter the new rate, new term, and refi fees (tax/title/etc.).
Review current vs new payment, remaining balance, interest totals, monthly savings, and breakeven months.
Check interest saved to see if the refi is worth the fees and term reset.

Inputs explained

Remaining balance: Current payoff amount on your existing auto loan.
Current rate/term elapsed: APR on the current loan and how many months have passed.
New rate/term: APR and term for the refinance offer.
Refi fees: Title, registration, lender fees. Enter total; assumed paid upfront (shown in results) but not financed.

How it works

We compute your original payment, simulate elapsed months to find today’s balance, and estimate remaining interest on the current path.

For the refi, we calculate a new payment on the remaining balance at the new rate/term, add refi fees, and total interest over the new term.

Savings = current remaining interest − new interest. Breakeven = refi fees ÷ monthly savings (if savings are positive).

Formula

Current payment = P × r(1+r)^n / [(1+r)^n − 1]; simulate elapsed months to get today’s balance.
New payment = Remaining balance × r_new / (1 − (1+r_new)^{−n_new}).
Breakeven = Refi fees ÷ (Current payment − New payment). Savings = Interest(current remaining) − Interest(new).

When to use it

Comparing a credit union refi offer to your dealer loan.
Testing if a lower rate offsets resetting to a longer term.
Checking breakeven when fees are high relative to monthly savings.
Seeing payment drop potential to improve monthly cash flow.

Tips & cautions

If fees are low and rate drops, breakeven can be just a few months—good if you’ll keep the car.
Shorter terms save more interest but may raise the payment—adjust term to fit budget.
If your credit improved, shop multiple offers; small APR drops can matter on remaining balance.
Avoid stretching the term too far; a low payment can still increase total interest.
Assumes fixed-rate amortization and on-time payments; no late fees or prepayment penalties modeled.
Does not model taxes/insurance/maintenance—P&I only.
Assumes refi fees are paid upfront, not financed; if financed, total interest would be slightly higher.
Does not model negative equity rolled into the new loan; enter actual payoff amount to be precise.

Worked examples

$22k remaining, 8% APR, 60 mo orig, 18 mo in → new 5.5%/60 mo, $350 fees

Current P&I ≈ $446; balance today ≈ $16,294
New P&I ≈ $311; monthly savings ≈ $135; breakeven ≈ 2.6 months
Interest saved ≈ $61 vs finishing the current loan

$18k remaining, 9.5% APR, 72 mo orig, 30 mo in → new 6.25%/60 mo, $500 fees

Current P&I ≈ $329; balance today ≈ $11,715
New P&I ≈ $228; monthly savings ≈ $101; breakeven ≈ 4.9 months
Interest saved ≈ $145 vs current path

Deep dive

This auto refinance calculator compares your current car loan to a refi offer, showing new payment, interest saved, and breakeven after fees so you can decide if it’s worth it.

Use it to test rate drops, different terms, and fee impacts before signing a refinance agreement.

FAQs

Should I finance the refi fees?: This model assumes fees are paid upfront. Financing them would raise total interest slightly; add them to the balance if you want to approximate that.
What if I extend the term?: Payment drops but total interest can rise. Check the interest saved line—if negative, you’re paying more overall.
Do taxes and insurance change?: No, this is P&I only. Your insurance/taxes don’t change because of the refinance.
Prepayment penalties?: Not modeled. Verify your current loan doesn’t charge a penalty for early payoff and that the new loan allows extra payments.
Negative equity rolled in?: Enter the true payoff as current balance to reflect any rolled-in negative equity. This model doesn’t separately track it.

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