Auto Loan Calculator
Calculate your monthly auto loan payment along with total interest and total cost of the car.
Example
A $30,000 car with $5,000 down and a $3,000 trade-in at 7% sales tax, financed over 60 months at 6% APR:
- Sales tax: ($30,000 − $3,000) × 7% = $1,890
- Amount financed: $30,000 − $5,000 − $3,000 + $1,890 = $23,890
- Monthly payment: $461.86
- Total interest: $3,821.64
- Total cost (incl. down + trade): $35,711.64
How it works
Enter the vehicle price, down payment, trade-in value, sales tax rate, loan term, and interest rate. Sales tax (on price minus trade-in) is added to the financed amount, then the standard amortization formula computes your monthly payment.
Good to know
The Auto Loan Calculator turns six numbers — vehicle price, down payment, trade-in value, sales tax rate, loan term, and interest rate — into a realistic monthly car payment, plus the amount financed, the sales tax dollar figure, total interest, and the all-in total cost of the car. It is built for car shoppers comparing financing scenarios before they sit down at a dealer, and for anyone who wants to sanity-check a quoted payment against the math behind it.
Reach for it when you're weighing how a bigger down payment, a longer term, or a different rate changes what you'll actually pay each month. Because every field recalculates as you type, it works well as a what-if tool: drop the term from 72 to 60 months and watch the monthly payment rise but total interest fall, or add a trade-in and see both the financed amount and the sales tax base shrink.
When reading the result, treat the big monthly number as the loan payment only — it does not include insurance, registration, or dealer fees. The two bars below split your financed balance into principal versus interest, so a long interest bar is a quick visual cue that the rate or term is costing you. Note that the total cost figure deliberately adds back your down payment and trade-in value, so it reflects the full economic price of the car rather than just the loan.
One caveat worth knowing: this tool credits your trade-in against the taxable amount, which matches most U.S. states but not all. If you live in a state that taxes the full purchase price, or you're financing add-ons, gap insurance, or doc fees, fold those into the vehicle price field so the financed amount and tax stay accurate.
Frequently asked questions
Is sales tax charged on the full price or after my trade-in?
This calculator applies sales tax to the vehicle price minus the trade-in value, which is how most U.S. states handle it (a trade-in tax credit). A few states tax the full purchase price, so check your state's rules if precision matters.
Why does my total cost include the down payment and trade-in?
Total cost reflects the complete amount you pay for the vehicle: your down payment, the value you gave up in your trade-in, plus every loan payment (principal, tax, and interest) over the full term.
Is my data uploaded anywhere?
No — this calculator runs entirely in your browser; nothing is uploaded.
Is this financial advice?
No. These are educational estimates — consult a qualified financial professional before making decisions.
People also ask
What is a good interest rate on a car loan?
Auto loan rates depend heavily on credit score, loan term, whether the car is new or used, and prevailing market rates, so there is no single benchmark. Borrowers with strong credit typically qualify for the lowest advertised rates, while longer terms and used vehicles often carry higher rates.
How much should I put down on a car?
A common rule of thumb cited for new cars is around 20% down and about 10% for used cars, though the right amount varies by budget and goals. A larger down payment lowers the amount financed, reduces total interest, and shrinks the monthly payment.
Is a 72-month car loan a bad idea?
Longer terms like 72 or 84 months lower the monthly payment but increase total interest paid and raise the risk of owing more than the car is worth. Whether it suits you depends on your budget and how long you plan to keep the vehicle.
Does a trade-in lower my sales tax?
In most U.S. states, the trade-in value is subtracted from the price before sales tax is calculated, reducing the tax owed. A handful of states tax the full purchase price regardless of trade-in, so the rules vary by location.
What's the difference between APR and interest rate on a car loan?
The interest rate is the cost of borrowing the principal, while APR (annual percentage rate) also reflects certain loan fees, making it a broader measure of cost. This calculator uses the interest rate you enter to compute payments and does not separately add lender fees.
Does this calculator include taxes and fees in the monthly payment?
It adds the calculated sales tax to the financed amount, but it does not include registration, title, documentation, or dealer fees. To account for those, add them into the vehicle price field before calculating.
How is a car loan monthly payment calculated?
It uses the standard amortization formula, which spreads the financed balance plus interest evenly across the loan term. The inputs are the principal financed, the monthly interest rate (annual rate divided by 12), and the number of months.
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