Car payment calculator: price, trade-in, tax and interest
Enter the vehicle price, cash down, trade-in details, local tax method, financed fees, annual interest rate and term. HitEquals estimates the amount financed, monthly car payment, total interest and a complete amortization schedule.
Inputs used by this calculator
Auto Loan Calculator uses the fields below. The starting values reproduce the page example; replace them with values from the same units and time period before using the result.
| Input | Starting example | Accepted value | How it is used |
|---|---|---|---|
| Vehicle price | 35,000 | 0 or greater | Supplies the vehicle price quantity used by the published equation or result breakdown. |
| Down payment | 5,000 | 0 or greater | Supplies the down payment quantity used by the published equation or result breakdown. |
| Trade-in value | 0 | 0 or greater | Supplies the trade-in value quantity used by the published equation or result breakdown. |
| Amount owed on trade-in | 0 | 0 or greater | Selects the unit or conversion path used by Auto Loan Calculator. |
| Sales tax rate (%) | 6.5 | 0 to 100 | Supplies the sales tax rate (%) quantity used by the published equation or result breakdown. |
| Tax calculation | Tax the full vehicle price | Tax the full vehicle price · Tax price after trade-in credit · Do not include sales tax | Chooses which Auto Loan Calculator method or unknown the engine evaluates. |
| Title, registration and other financed fees | 750 | 0 or greater | Supplies the title, registration and other financed fees quantity used by the published equation or result breakdown. |
| Annual interest rate (%) | 6.5 | 0 to 100 | Supplies the annual interest rate (%) quantity used by the published equation or result breakdown. |
| Loan term (years) | 5 | 0.0833333333 to 10 | Supplies the loan term (years) quantity used by the published equation or result breakdown. |
How to calculate a car payment
Start with the out-the-door components rather than the advertised vehicle price alone. Add applicable sales tax and financed fees, subtract the down payment and trade-in value, then add any loan balance still owed on the trade-in.
The resulting amount financed is amortized over the selected number of monthly payments. The calculator separates the purchase inputs from the interest calculation so a dealer quote can be checked line by line.
- Enter the negotiated vehicle price.
- Add cash down and both sides of any trade-in.
- Choose the tax treatment and enter financed fees.
- Enter APR and term, then compare the payment and total interest.
Car loan payment formula
For a fixed-rate installment loan, the monthly payment depends on principal P, monthly rate r and number of payments n. The annual note rate is divided by 12 and by 100 to obtain r. At zero interest, payment is simply principal divided by n.
payment = P × r ÷ (1 − (1 + r)⁻ⁿ)r = annual interest rate ÷ 12 ÷ 100zero-rate payment = P ÷ nAmount financed and out-the-door price
Vehicle price and amount financed are different numbers. Taxes, title, registration, documentation products and optional add-ons can raise the amount; cash and positive trade-in equity reduce it.
This tool treats fees as financed because that is the conservative default for a payment estimate. If a fee will be paid in cash, leave it out of the financed-fees field and include it separately in your purchase budget.
trade-in equity = trade-in value − amount owedamount financed = price + tax + fees − down − trade-in equityTrade-in value and negative equity
If the vehicle is worth more than its payoff amount, the difference is positive equity and lowers the new loan. If the payoff is larger, the difference is negative equity and rolling it into the next loan increases both payment and interest.
The CFPB recommends comparing the amount financed, APR, loan length and monthly payment across offers. A lower payment obtained only by extending the term can cost more overall.
Sales tax and fees
US sales-tax rules differ. Some transactions tax the full selling price, some allow a trade-in credit, and some vehicles or buyers may receive different treatment. The three tax modes make the assumption explicit instead of silently choosing one rule.
Dealer documentation, destination, title and registration charges also vary. Use the buyer's order or written quote to replace the default estimate before relying on the result.
Interest rate, APR, term and total interest
The payment formula uses the annual interest rate on the note. The disclosed APR is a broader comparison measure that can include certain finance charges, so it may be higher and should be compared separately across offers. A longer term usually lowers the monthly payment but keeps the balance outstanding longer.
The FTC advises getting the total cost in writing and comparing financing terms, including APR, number of payments and the amount of each payment. Monthly affordability alone does not show the full cost.
What this estimate excludes
The result excludes recurring insurance, fuel, maintenance, parking and future registration renewals. It also does not model rebates, promotional conditions, variable rates, late charges, prepayment rules or loan products with balloon payments.
Rounding can make the lender's final payment differ by a few cents. The signed contract and lender disclosure control the actual obligation.
How loan term changes the same financed amount
| Term | Approx. monthly payment | Approx. total interest |
|---|---|---|
| 36 months | $919.47 | $3,100.92 |
| 48 months | $711.45 | $4,149.53 |
| 60 months | $586.98 | $5,219.07 |
| 72 months | $504.30 | $6,309.45 |
Frequently asked questions
How is a car payment calculated?
The amount financed is amortized using the monthly interest rate and number of payments. Taxes, fees, down payment and trade-in equity determine the principal.
Does a trade-in reduce sales tax?
It depends on the state and transaction. Choose the full-price or after-trade-in tax mode that matches the written quote.
What happens if I owe more than my trade-in is worth?
The difference is negative equity. If rolled into the new loan, it increases the amount financed and the interest paid.
Is APR the same as the interest rate?
No. The payment formula uses the note's interest rate. APR is a broader standardized annual cost that can include certain finance charges, so compare it separately across offers.
Why can a longer car loan cost more?
More payments can lower the monthly amount while interest accrues over a longer period, increasing total interest.
Does the estimate include car insurance?
No. Insurance, fuel, maintenance, parking and future registration renewals are ownership costs outside this loan payment.
What to keep in mind
US-oriented estimate. Tax treatment, fees, rebates and trade-in credits vary by state and transaction. Confirm the itemized out-the-door price, interest rate, disclosed APR and payment schedule with the lender before signing.
Results are rounded for display in US format, with money in dollars and cents; CSV exports keep full calculation precision. This is a calculation summary, not an official certificate.