Price a car properly before you visit the dealer. Enter the vehicle price, down payment, trade-in value, sales tax and fees to see the amount you actually finance, the monthly payment and the total cost of the loan.
Auto Loan Calculator
How the Auto Loan Calculator Works
A car’s sticker price is not what you finance. This calculator builds the real loan amount the way a dealer does — starting from the vehicle price, subtracting your down payment and trade-in, then adding sales tax and fees — and then works out the monthly payment and total cost. Buyers use it to check a dealer’s numbers, compare offers between dealerships, and see what a car truly costs once interest is included, before anything is signed.
First it calculates the amount financed: Amount financed = Price − Down payment − Trade-in + Sales tax + Fees. In this calculator the sales tax is charged on the price minus the trade-in value, which is how many US states treat trade-ins. The monthly payment then comes from the standard loan formula: M = P × r(1 + r)^n ÷ ((1 + r)^n − 1), where P is the amount financed, r is the APR divided by 100 and then by 12, and n is the term in months, which you enter directly for car loans.
The estimate assumes a fixed APR and equal monthly payments for the whole term. Tax rules differ by state — some tax the full price, some give no trade-in credit — and dealer fees vary, so adjust the tax and fee fields to match your local quote. The total cost shown includes your down payment and trade-in value, giving the full out-of-pocket picture.
How to Use This Calculator
- Enter the vehicle’s purchase price.
- Enter your cash down payment and the trade-in value of your current vehicle, if you have one.
- Enter your local sales tax rate and any dealer or documentation fees.
- Enter the loan term in months (36, 48, 60, and 72 are common) and the APR you have been offered.
- Press Calculate to see the amount financed, the monthly payment, the total interest, and the total cost of buying the car.
Example
Buy a $30,000 car with a $5,000 down payment, no trade-in, and — to keep it simple — no tax or fees. The amount financed is $25,000. Over 60 months at 6% APR, the monthly payment is $483.32 and the total interest comes to about $3,999, so the loan itself costs roughly $28,999 on top of your $5,000 down payment.
Now a fuller example: a $45,000 vehicle with $5,000 down, a $5,000 trade-in, 7% sales tax, and $500 in fees. The tax is charged on $40,000 (price minus trade-in), adding $2,800, so the amount financed is $38,300. Over 72 months at 7.5% APR the payment is $662.21 a month, total interest is $9,379.21, and the total cost of the car including down payment and trade-in is $57,679.21.
What Affects the Result
- Down payment and trade-in — both reduce the amount financed dollar for dollar, which cuts the payment and the interest.
- APR — dealer financing, bank, and credit union rates can differ by several points; on a five- or six-year loan that gap is worth real money.
- Term length — 72- and 84-month loans shrink the payment but add interest and increase the risk of owing more than the car is worth.
- Sales tax and fees — these are easy to forget and can add thousands to the amount financed.
- Practical tip — negotiate the car’s price first, then discuss financing. A great rate on an inflated price is still a bad deal.
It is also worth running your chosen deal at a shorter term before you sign, because the difference is often smaller monthly than people fear and larger in savings than they expect. The $25,000 loan from the first example, repaid over 48 months instead of 60 at the same 6% APR, raises the payment from $483.32 to $587.13 — about $104 more a month — but cuts the total interest from about $3,999 to $3,182.03 and leaves you owning the car outright a full year earlier. Shorter loans also protect you against owing more than the car is worth, a real risk on long terms because cars lose value fastest in their first years while the loan balance falls slowly. If the shorter payment fits your budget, it is usually the cheaper way to buy the same car.
Finally, when a dealer offers a choice between a cash rebate and a cut-price APR, this calculator settles the argument with numbers instead of instinct: run the deal both ways — full price at the low rate, then the rebated price at the standard rate — and compare the total cost lines. The rebate wins surprisingly often on shorter terms, while the cheap rate wins on longer ones.
Auto Loan Calculator FAQs
Is sales tax calculated on the full price?
In this calculator, tax is charged on the price minus your trade-in value, matching the rule in many states. Some states tax the full price instead — if yours does, enter a trade-in of zero and adjust, or treat the result as a close estimate.
What is a sensible auto loan term?
Shorter terms cost less in interest and build equity in the car faster. Longer terms lower the monthly payment but raise the total interest, as the second example shows. Many buyers aim for 60 months or less, but the right term depends on your budget.
Does the calculator include insurance and running costs?
No. It covers the purchase: price, tax, fees, financing, and interest. Insurance, fuel, maintenance, and registration are separate ownership costs to budget for on top.
Why is the total cost higher than the car’s price?
Because of interest, tax, and fees. In the second example, a $45,000 car costs $57,679.21 in total once $9,379.21 of interest, $2,800 of tax, and $500 of fees are included. That gap is exactly what this calculator is for.
Can I use this for a motorcycle, boat, or RV loan?
Yes — the maths is the same for any vehicle bought with a fixed-rate loan. Enter the price, your down payment and trade-in, tax, fees, term, and APR, and the results work the same way.
Related calculators: Loan Calculator, Interest Rate Calculator, Mortgage Calculator.