Auto Loan Calculator
Estimate your monthly car payment with down payment, trade-in and payoff, rebates, sales tax and fees — or find the car price a monthly budget buys — with a term comparison and amortization schedule.
How it works
Taxable price = price − trade-in (in most states) · Amount financed = price − rebate − down payment − (trade-in − amount owed) + sales tax + fees (if rolled in) · M = P × r ÷ (1 − (1 + r)^−n)
Sales tax is worked out first. Most US states tax the price after subtracting your trade-in, and most tax the price before any manufacturer rebate; both rules can be switched under More options for states that work differently (if the price already includes VAT or tax, set the tax to 0%). The amount financed is the price minus the rebate, your down payment and your trade-in equity — the trade-in value minus what you still owe on it. If you owe more than the trade-in is worth, that negative equity is added to the new loan. Tax and fees are added to the loan when you roll them in; otherwise they are paid at signing along with the down payment. The financed amount then amortizes like any fixed-rate loan: r is the monthly rate (annual ÷ 12) and n the number of months. The total cost of the car adds up the price after rebate, tax, fees and interest. In “Car price I can afford” mode the same steps run backwards from the monthly payment you can manage. The term table shows how the payment and the total interest change between 36 and 84 months.
Worked example
A $32,000 car with 7% sales tax and no trade-in has $2,240 of tax. With $4,000 down and tax rolled into the loan, you finance $30,240 at 7.5% for 60 months: about $605.95 a month and $6,116.85 of interest, so the car costs $40,356.85 in total. Trading in a car worth $8,000 that still has $10,000 owing changes things: the trade-in cuts the taxable price to $24,000 ($1,680 tax), but the $2,000 of negative equity is added, so you finance $31,680 and pay $634.80 a month. With a $600 monthly budget, the same rate, term, down payment and tax buy a car priced at about $31,723.
Sources: CFPB — Auto loan key terms · CFPB — Should I trade in my car if it’s not paid off? (negative equity) · CFPB — What is amortization and how could it affect my auto loan?
Frequently asked questions
Is a longer term better?
A 72- or 84-month loan lowers the payment but raises the total interest and keeps you owing more than the car is worth for longer. The term table under the results shows the payment and total cost for 36 to 84 months side by side; 60 months or less is the usual guidance.
Does my trade-in reduce the sales tax?
In most US states, yes: tax is charged on the price minus the trade-in value. A few states, including California, Hawaii, Kentucky, Maryland, Michigan, Montana, Virginia and DC, tax the full price. Switch “Trade-in lowers the taxable price” under More options to match your state.
What if I owe more on my trade-in than it is worth?
Enter the payoff in “Amount owed on trade-in”. The shortfall, called negative equity, is added to the new loan, which raises the payment and the interest. The calculator shows the amount, and the loan-to-value result tells you how much you owe compared with the car’s price.
Should I roll tax and fees into the loan?
Rolling them in means less cash at signing but more interest, because you borrow them too. Turn the switch off to pay them up front; the “Upfront payment” result shows how much cash you need on the day.
How much car can I afford?
Choose “Car price I can afford” and enter the monthly payment that fits your budget. The calculator works backwards through the term, rate, tax, fees, down payment and trade-in to the highest vehicle price that payment covers. A common guideline is to keep the car payment under about 10%–15% of take-home pay.
What credit score gets the advertised rates?
The lowest advertised APRs generally require excellent credit. Used-car rates usually run several points higher than new-car rates, so check your own pre-approved rate before you shop.
Related calculators
This is an educational estimate, not financial advice. Lenders use their own rounding, fees and credit terms — confirm exact figures with your lender or a licensed advisor.