Auto Loan Calculator — Car Payment With Trade-In & Tax
The dealer wants you to think in monthly payments; you should think in total cost. Enter the price, your down payment and trade-in, the sales tax and your loan terms — this calculator shows the honest monthly payment and what the car really costs you once interest is counted.
Documentation fees, registration and dealer add-ons vary by state/country and are not included — ask for the out-the-door price and put it in the price field for full accuracy.
How to use this tool
- Enter the negotiated vehicle price (before add-ons and fees).
- Add your cash down payment and any trade-in value.
- Enter your local sales tax rate and the APR you've been offered.
- Compare 48 vs 60 vs 72 months — watch how the \"cheap\" longer payment inflates the true total cost.
Frequently asked questions
Why do dealers push longer loan terms?
A 72- or 84-month loan makes an expensive car look affordable monthly, while dramatically increasing total interest — and the dealer often earns on the financing. It also leaves you \"underwater\" (owing more than the car is worth) for years. If you need 84 months to afford it, the car is too expensive.
What credit score gets the best auto loan rates?
Top rates typically require scores above ~720; below ~600, rates can exceed 15%. Before visiting a dealer, get pre-approved by your own bank or credit union — it gives you a benchmark and negotiating power against the dealer's financing offer.
Should I use the rebate or the low APR promotion?
Manufacturers often offer either a cash rebate or promotional 0–2.9% financing, not both. Run this calculator twice: once with (price − rebate) at your bank's normal rate, once at full price with the promo rate. The bigger the loan and longer the term, the more the low APR tends to win.
How much should my down payment be?
A useful guideline: 20% down on a new car, 10% on used, with a term of 48 months or less. This roughly matches depreciation so you're never owing more than the car's value.
Is 20% of my income too much for a car payment?
Most planners suggest all car costs — payment, insurance, fuel, maintenance — stay under 15–20% of take-home pay, with the loan payment alone under ~10%. Cars are depreciating assets; every extra dollar there is a dollar not compounding somewhere useful.