Auto Loan Calculator
Calculate your monthly car payment and total cost including trade-in, taxes, and fees.
Work out your monthly car payment and true total cost by combining the vehicle price, sales tax, fees, trade-in credit, and down payment into a single amortizing auto loan.
How Auto Loan Calculator Works
The calculator first works out how much you actually need to finance: it takes the vehicle price, adds sales tax (price × tax rate) and any fees, then subtracts your down payment and trade-in value. This financed amount — not the sticker price — is what the loan payment is based on.
From there it applies the standard amortizing-loan formula: monthly payment = P × [r(1+r)^n] / [(1+r)^n − 1], where P is the financed amount, r is the annual interest rate divided by 12, and n is the loan term in months (24 to 84, selected from the term dropdown).
Total interest is the sum of all monthly payments minus the financed amount, and the cost breakdown panel lists the price, tax, fees, and credits separately so you can see exactly how the financed amount was built before interest is added on top.
See It In Action
Who Uses Auto Loan Calculator and Why
- Working out the real monthly payment on a car purchase once sales tax, dealer fees, and a trade-in are all factored in, not just the sticker price.
- Comparing how a trade-in versus no trade-in changes the amount you actually need to finance.
- Testing a few loan terms (like 60 vs. 72 months) on the same vehicle price to see the tradeoff between payment size and total interest.
- Checking whether a dealer's quoted monthly payment lines up with the math once tax and fees are added to the vehicle price.
Mistakes to Avoid
- Entering your outstanding trade-in loan payoff amount instead of your net trade-in equity — the calculator expects the trade-in's value minus what you still owe on it, not the full trade-in value or the payoff figure alone.
- Forgetting that sales tax is calculated on the vehicle price before your down payment and trade-in are subtracted, so a low down payment plus a high tax rate can leave the financed amount close to or above the sticker price.
- Overlooking dealer fees entirely — fees are added into the financed amount just like tax, so leaving that field at zero understates what you'll actually be borrowing.
Tips for Best Results
- Calculate your net trade-in equity (trade-in value minus any amount you still owe on it) before entering it, since the calculator doesn't track an existing trade-in loan separately.
- Compare a few loan terms side by side — a longer term lowers the monthly payment but the example math shows total interest climbs meaningfully as months are added.
Fixing Common Problems
My financed amount looks higher than the vehicle's sticker price. — This happens when sales tax and fees outweigh your down payment and trade-in credit — check that your down payment and trade-in equity are both entered, since those are the only two amounts that reduce the financed total.
Terms Explained
Financed amount: The actual loan principal being borrowed: vehicle price plus sales tax and fees, minus down payment and trade-in equity.
Trade-in equity: The net value of a trade-in vehicle after subtracting anything still owed on it — the figure this calculator expects, not the vehicle's raw value.