Auto Loan Calculator
Price a vehicle loan: subtract down payment and trade-in from the car price to get the amount financed, then see monthly payment, total interest, and schedule totals.
Calculate
Calculate
Result
The formula
Amount financed = price − down payment − trade-in. Monthly payment uses the standard amortizing loan formula with monthly rate r = APR/12 and n months — the same engine family as our personal loan calculator.
Worked example
- Price $30,000 − $3,000 down − $2,000 trade-in = $25,000 financed
- APR 6%, term 60 months → r = 0.005
- Payment ≈ $483.32/mo
Result: ≈ $483/mo · interest and totals in the result grid
How auto loan payments are calculated
Dealers quote payment from the financed amount after cash down and trade equity — not from sticker price alone.
Principal after down and trade-in
We subtract cash down and trade-in allowance from the vehicle price. Taxes, fees, gap insurance, and negative equity rolled into the loan are not auto-added — increase price or reduce down if those apply.
Amortization
Equal monthly payments cover interest first; the rest reduces principal. Longer terms lower the payment but raise lifetime interest — a common auto-finance trade-off.
APR vs dealer “rate”
Compare APR and total cost, not only the monthly payment. Add-ons and extended warranties can inflate the amount financed.
Interesting facts
Payment vs total cost
A lower monthly payment from a longer term usually means more interest overall.
Trade-in equity
Trade-in value reduces what you finance; if you owe more than the trade is worth, negative equity may be rolled in (not auto-modeled here).
Same math as personal loans
Fixed-rate amortizing auto loans use the same payment formula as other installment loans.
Cash vs finance
Compare total interest and opportunity cost of cash — not only the advertised monthly payment.
Prepayment
Many auto loans allow extra principal payments; check for prepayment penalties.
Frequently asked questions
Enter vehicle price, down payment, trade-in, APR, and term in months. We finance (price − down − trade-in) with the standard amortization formula.
Not automatically. Add tax/fees into the price field or reduce your down payment if they are financed.
Same payment math — this page adds auto-specific labels for price, down payment, and trade-in.
Shorter terms cost more per month and less interest. Longer terms do the opposite. Match the term to how long you will keep the car.
Trade-in value is subtracted from the vehicle price before financing, along with your down payment. A larger trade-in lowers the amount financed and therefore the monthly payment and total interest.
It depends on credit score, loan term, and whether the vehicle is new or used — lenders publish rate tiers by these factors. Compare offers from multiple lenders and enter each APR here to see the payment difference.
Usually yes — it reduces the amount financed, which lowers both the monthly payment and total interest paid over the loan, as long as the rate and term stay the same.
References
- Shopping for a loan Consumer tips for comparing installment credit.
- What is APR? Note rate vs APR.