Online Tool Store
Car Loan Calculator
Calculate monthly car payments including trade-in value, down payment, and sales tax, plus the full amortization schedule. Runs entirely in your browser.
This works right here on your device — nothing gets sent out.
How the car loan calculator works
- Enter the vehicle price, trade-in value and any amount still owed on it, down payment, and fees.
- Enter the sales tax rate, annual interest rate (APR), and loan term in months.
- Review the estimated monthly payment, amount financed, sales tax, total interest, and the full payment-by-payment schedule, which you can download as a CSV file.
The formula
Sales tax applies to the vehicle price minus your trade-in's full value. Any loan still owed on that trade-in only affects how much of its value is left as equity toward the new purchase — if you owe more than it's worth, that negative equity is added to what you finance. The monthly payment then follows the standard fixed-payment amortization formula:
Sales tax = (Vehicle price − Trade-in value) × Tax rate Trade-in equity = Trade-in value − Amount owed on trade-in Amount financed = Vehicle price − Trade-in equity − Down payment + Sales tax + Financed fees Payment = P × r / (1 − (1 + r)⁻ⁿ)
where P is the amount financed, r is the monthly interest rate (APR ÷ 12), and n is the number of monthly payments. Example: a $32,000 car with a $5,000 trade-in (paid off), $3,000 down, no financed fees, 7% sales tax, 6.9% APR, and a 60-month term finances about $25,890 and comes to roughly $511/month. This estimate assumes a fixed interest rate and equal monthly payments. It does not include dealer add-ons or extended warranties beyond the fees you enter, and trade-in tax treatment varies by state and country — check your local rules.
FAQ
Does the trade-in value reduce the taxable amount?
This calculator assumes it does — sales tax is calculated on the vehicle price minus your trade-in value, which is how many U.S. states handle it. Some states and countries tax the full price regardless of trade-in, so set the tax rate to 0% and add tax to the vehicle price yourself if that's how your local rules work.
Is the down payment taxed?
No — this calculator only applies sales tax to the price minus your trade-in, then subtracts the down payment separately. That matches how most lenders structure the amount financed.
What loan term should I use?
Auto loans commonly run 36 to 72 months, sometimes up to 84. A shorter term means higher monthly payments but less total interest paid over the life of the loan.
Does this include registration, documentation, or dealer fees?
Enter your title, registration, and documentation fees in the fees field, and choose whether to add them to your loan amount or pay them upfront. Fees are not taxed separately from the vehicle price in this calculator, matching how most dealers itemize them.
What if I still owe money on my trade-in?
Enter the amount you still owe as "Amount still owed on trade-in." If that is more than the trade-in value, the difference — known as negative equity — is added to your new loan, which is how dealers commonly handle it. Leave this at 0 if your trade-in is paid off.
Is my information saved or uploaded anywhere?
No. Every number you enter and the entire calculation stay in your browser — nothing is sent to a server.
How we compare
| Feature | Online Tool Store | Calculator.net | NerdWallet | Omni Calculator |
|---|---|---|---|---|
| Accounts for a loan still owed on your trade-in | ✓ | ✓ | ✓ | ✗ |
| Title, registration, or documentation fees as their own field | ✓ | ✓ | ✓ | ✗ |
| Full amortization schedule you can download as a CSV file | ✓ | ✗ | ✗ | ✗ |
| No lender offers or loan ads shown | ✓ | ✓ | ✗ | ✓ |
| Embeddable on your own site | ✓ | ✗ | ✗ | ✗ |
Calculator.net and NerdWallet both let you account for a trade-in loan payoff and separate fees, same as this tool now does. NerdWallet pairs its calculator with lender offer cards; Calculator.net has print and save options rather than a CSV file. If you want that full picture without loan ads and with a schedule you can open in a spreadsheet, Car Loan Calculator is the straightforward choice — everything above runs on your device, in this tab.