What will my car payment be?

The loan is not the sticker price. The amount you finance is the price plus sales tax and fees, minus your down payment and the trade-in credit, plus whatever is still owed on the trade-in, because that balance has to be paid off and dealers roll it into the new loan. The payment then comes from the standard amortization formula: the annual rate divided by twelve, and the one fixed amount that retires the balance exactly at the end of the term. At 0%, a promotional rate, the formula collapses to the amount divided by the months.

Sales tax is an explicit input, not a hidden guess. There is no national rate, so the field starts at zero and you enter your combined state and local rate. The model taxes the price after the trade-in credit, which is how most states with a trade-in allowance work; a few states tax the full price. Fees are the title, registration, and doc charges on the contract, and both ride into the amount financed unless you pay them in cash.

The result reports two totals most car calculators skip. The loan's cost: the amount financed plus every dollar of interest on it. And the all-in cost of the car: price, tax, fees, and interest together, which is the number to compare against the sticker when a longer term makes the payment look easy.

The default rate is a published statistic, not a guess: the Federal Reserve's G.19 average for a 60-month new-car loan at commercial banks. The price is an example to be replaced, and everything else defaults to zero because it is yours to enter. Every figure on this page and in the JSON twin comes from one function, so the two never drift.

At the published default rate with nothing down, $35,000 over 60 months costs $695 a month. You pay $6,721 of interest, 19% of the price, so the car really costs $41,721 before tax, fees, insurance, or a single tank of gas. Stretch the same loan to 72 months and the payment drops to $599 while the interest rises to $8,133.

Here is that trade across common prices at the default rate: the payment and interest over 60 months, then over 72. Change any input above and the page recomputes as you type.

The table assumes the whole price is financed with no tax or fees, which flatters every row: your state's tax alone can add several payments' worth of amount financed. The 72-month column is the one dealers quote first because the payment looks better; the interest column beside it is what the look costs.

The calculator ranks its own drivers above, in dollars per step, for the inputs you entered. The steps are the sizes people actually negotiate in: a point of rate, a thousand dollars of price or down payment, a year of term.

The rate is where the credit union earns its visit. A point on the default loan adds $17 a month and $1,000 of interest over the loan, and dealer financing is a quote to beat, not an assignment. Arrive with an approval in hand and let the finance office try to do better.

The term is the payment lever with a hidden price. Each extra year takes the payment down and the interest up, and it stretches the months where you owe more than the car is worth. The term control under the number prices every common length for your inputs.

The price and the down payment move the loan dollar for dollar, but in opposite directions, and the price also drags tax with it where you pay sales tax. A thousand dollars negotiated off the price beats a thousand dollars of down payment for exactly that reason.

Your rate. The default is a national average for new cars at commercial banks; actual pricing moves sharply with credit tier, and used cars and longer terms price higher. Manufacturer incentives are not modeled either: a captive lender's promotional rate or a cash rebate you can take instead is a real choice this page can only price one side of at a time. Run it once with each offer and compare the all-in figures.

Your state's tax rules. The tax field is one combined rate applied to the price after the trade-in credit; a few states tax the full price, some cap the credit, and local rates vary within a state. The exact treatment is on the dealer's worksheet, and the field accepts whatever effective rate reproduces it.

The costs of owning. Insurance, registration renewals, fuel, and maintenance sit outside the loan, and gap insurance, which covers the wedge between what you owe and what the car is worth, is a separate purchase this page does not price. It only shows you the negative equity that makes gap coverage worth asking about.

This calculator is built to be used without a browser. Every input is a query parameter on this page, and the same parameters on the JSON twin return the complete answer as a document.

GET /tools/auto-loan.json?price=42000&down=5000&rate=7.14

The response carries inputs after parsing and clamping, result with the payment, the amount financed, the tax and fees, the interest, the loan's total cost and the all-in cost of the car, the yearly rows, plus sensitivity tables by term, rate, and down payment, drivers ranked by effect with a plain sentence each, assumptions that say for every field whether you supplied it and which source the default came from, sources with URLs and as-of dates, warnings, a disclaimer, and in tool the canonicalUrl and jsonUrl that carry only your non-default parameters. The canonical URL is the answer's permanent address; use it when you cite the number.

Parameters, all optional, in any order:

• price ($), default $35,000.
• down ($), default $0.
• tradeIn ($), default $0.
• owedOnTrade ($), default $0.
• salesTax (%), default 0%.
• fees ($), default $0.
• rate (%), default 7.14%, from Federal Reserve, G.19 Consumer Credit (June 2026 data).
• term (months), default 60 months.

Values accept plain numbers and loose human formats such as 100k, $100,000, or 6.5%. Unknown parameters are ignored, values outside a field's range are clamped and reported in warnings, and the endpoint never fails on bad input. Responses are cacheable for a day; the defaults change when their sources publish, and tool.version changes when the method does.

• Federal Reserve, G.19 Consumer Credit (June 2026 data), as of 2026-08-07. Commercial bank interest rates, May 2026: 24-month personal loans 11.86%; 60-month new car loans 7.14%; credit card accounts assessed interest 22.15%.

Default values on this page: rate 7.14%, from Federal Reserve, G.19 Consumer Credit (June 2026 data). The price default is an example, and the down payment, trade-in, balance owed, sales tax, and fees default to zero because they are yours to enter; sales tax has no national default.

Carlo is a personal finance agent. It knows your accounts, debts, and goals, so instead of a payment on an example car it can tell you what this loan does to your savings rate, your insurance line, and the other things you are working toward. Text it the question.

ask carlo anything(415) 376-5678