Auto Loan Calculator
Work out your real car payment, not just principal and interest. Add the vehicle price, sales tax, down payment, trade-in, fees and incentives to see the financed amount, the up-front cash, total interest and the all-in cost. Or flip to budget mode to find the price you can afford from a monthly payment.
Formula
Worked example
A $30,000 car with $3,000 down and 6% sales tax: tax is $1,800, and rolling $1,800 tax plus $500 fees into the loan finances $29,300. At 7.5% over 60 months that is about $587 per month and roughly $35,200 paid, about $40,000 out the door.
How the Calculation Works
The calculator applies the standard amortization formula, converting your annual interest rate to a monthly rate and compounding it over the number of monthly payments. Each payment covers accrued interest first, with the remainder reducing your principal balance. This means early payments are weighted more heavily toward interest, while later payments chip away more at principal, a pattern known as front-loaded amortization.
Three modes: price, loan amount, or budget
Choose how you want to start. In price mode you enter the vehicle price and the calculator layers on sales tax, title and registration fees, your down payment, trade-in equity and any cash rebates, then shows the financed amount, the up-front cash, the total interest and the all-in out-the-door cost. In loan amount mode you skip straight to the principal you are financing for a quick principal-and-interest payment. In budget mode the math runs in reverse: enter the monthly payment you can afford and the calculator solves for the loan principal that fits, so you know how much car to shop for. Select your currency if you are outside the US.
How sales tax, trade-ins and fees are handled
Most US states tax the vehicle price minus your trade-in allowance, which is why a trade-in lowers both the loan and the tax bill. The calculator applies your sales tax rate to that reduced base. Title, registration and dealer fees are added on top. You decide whether tax and fees are rolled into the loan, which spreads them across the term but accrues interest, or paid up front with your down payment. Negative equity, where you still owe more on your trade-in than it is worth, rolls into the new loan and increases the amount financed.
What Affects Your Monthly Payment
A higher principal, a longer term, or a higher interest rate each increases the total interest you pay, though a longer term lowers the individual monthly payment. Your credit score is the primary driver of the interest rate a lender offers: borrowers with scores above 720 typically qualify for rates significantly below the national average, while subprime borrowers may face rates several percentage points higher. A larger down payment reduces the principal and therefore both the monthly payment and total interest.
Limitations and What Is Not Included
This calculator covers principal and interest only. It does not account for sales tax, title and registration fees, dealer documentation fees, extended warranties, or gap insurance, all of which add to your out-of-pocket cost. If your lender requires private mortgage-equivalent products or charges an origination fee, those costs will not appear here. Treat the output as an estimate for comparison and planning purposes; always confirm the exact payment schedule with your lender before signing a contract.
Frequently asked questions
What is a good interest rate on an auto loan?
According to the Consumer Financial Protection Bureau and industry data, borrowers with excellent credit (720+) have historically secured new-car rates in the 5-7% range, while the national average across all credit tiers is often several points higher. Rates fluctuate with Federal Reserve policy, so the best rate available to you depends on both your credit profile and current market conditions. Shopping at least three lenders, including your own bank or credit union, typically yields the most competitive offer.
Is it better to choose a shorter or longer loan term?
A shorter term (36-48 months) means a higher monthly payment but substantially less total interest paid over the life of the loan. A longer term (60-84 months) lowers the monthly payment but increases total interest and raises the risk of being underwater on the loan, owing more than the car is worth, for a longer period. Financial planners generally recommend the shortest term whose payment fits comfortably within your budget.
Does this calculator include sales tax and fees?
Yes, in price mode. Enter the vehicle price and your sales tax rate, plus any title, registration and dealer fees, and the calculator computes the tax (on the price minus your trade-in, as most states do), shows the up-front cash, and reports the all-in out-the-door cost. You can choose whether tax and fees are rolled into the loan or paid up front. If you only want a quick principal-and-interest figure, switch to loan amount mode.
How does the budget mode work?
Budget mode reverse-solves the loan. Instead of entering a price, you enter the monthly payment you can afford along with the rate and term, and the calculator inverts the amortization formula to find the largest loan principal that payment can carry. Add your planned down payment and trade-in equity on top of that figure to get the full vehicle price you can shop for. It is the fastest way to turn a monthly budget into a realistic price ceiling.
Should I roll taxes and fees into the loan?
Rolling tax and fees into the loan keeps your up-front cash low but means you pay interest on those charges for the whole term, raising the total cost. Paying them up front avoids that interest but requires more cash at signing. Toggle the option in the calculator to compare both, the amount financed, monthly payment and total cost update instantly so you can see the trade-off in your own numbers.