Car Loan Calculator
Estimate your monthly car loan payment including sales tax, down payment and trade-in.
This tool runs entirely in your browser. Your files are never uploaded to a server.
Sales tax is charged on the price minus trade-in (a common convention, not every jurisdiction's rule), then financed alongside the vehicle price minus the down payment and trade-in; fees, registration and add-ons are not included.
506.57
Monthly payment
25890.00
Amount financed
1890.00
Sales tax
4504.05
Total interest
30394.05
Total paid
What this calculator does
Estimates a fixed-rate auto loan's monthly payment by combining the vehicle price with sales tax, a down payment and a trade-in value into a single financed amount, then applying the standard installment-loan formula.
How to use it
Enter the vehicle price, down payment, trade-in value, sales tax rate, a nominal annual interest rate, and the loan term in months (up to 120). Keep every monetary field in the same currency.
Worked example
For a 32,000 vehicle with a 3,000 down payment, a 5,000 trade-in, 7% sales tax and a 6.5% loan over 60 months, sales tax is 1,890 (charged on 27,000, the price minus the trade-in), the amount financed is 25,890, the monthly payment is about 506.57, total interest over the term is about 4,504.05, and the total paid is about 30,394.05. Automated tests verify these figures.
Formula and sales tax
For financed amount P, monthly rate r and n monthly payments, payment = P × r ÷ [1 − (1 + r)^−n]; at 0% interest the amount is divided evenly across the months. Sales tax here is calculated on the price minus the trade-in value — the convention many US states use — not on the full price; some states tax the full price instead, so check your local rule if the estimate needs to be exact.
What is included and what isn't
The amount financed adds sales tax to the vehicle price and subtracts the down payment and trade-in value. It does not add dealer fees, documentation fees, title/registration costs, extended warranties or GAP insurance — any of these you plan to finance should be added to the vehicle price manually before entering it.
Assumptions and limits
The model assumes one constant nominal annual rate, monthly compounding, and every payment made in full for the loan's whole term (capped at 120 months here, since consumer auto loans rarely run longer). It does not model a variable rate, a balloon payment, early payoff, or a lender's specific underwriting and rounding rules.
Currency and regional limits
The fields are currency-neutral: 32,000 can mean dollars, euros or another unit, but every monetary field must use the same one. Sales tax rules — what's taxed, and at what rate — vary widely by country, state and even city, so the entered percentage and the price-minus-trade-in convention should be adjusted to match your own jurisdiction.
Interpretation, sources and privacy
This is an educational estimate, not a loan offer, pre-approval, or financial, tax or legal advice. The payment formula matches the standard fixed-rate installment-loan calculation used across lending; the trade-in-based sales tax convention reflects common practice in many US states, not a universal rule. Calculation runs locally in the browser; Quiklio does not upload the entered values. Confirm real terms with your dealer or lender.
Frequently Asked Questions
- Is sales tax always calculated on the price minus the trade-in?
- No — that's a common convention in many US states, but some states and countries tax the full vehicle price regardless of a trade-in, or don't apply a comparable sales tax at all. Adjust the sales tax field to match your own rules, or set it to 0 if it doesn't apply.
- What isn't included in the amount financed?
- Dealer fees, documentation fees, title and registration costs, extended warranties and add-ons like GAP insurance aren't added automatically — if you're financing any of them, include their cost in the vehicle price before entering it.
- Is my data uploaded anywhere?
- No — the calculation runs entirely in your browser using the values you type in. Nothing is sent to a server.