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The number the dealer shows is the payment. The numbers that matter are the interest and the real total cost of the car — here are all three.
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Last reviewed: July 20, 2026 · Formulas verified by automated tests before every release.
What dealers won't emphasize
- They sell payments, not prices. "Only $399/month" over 84 months costs far more than $450 over 60. Always compare total cost, not monthly comfort.
- Rate markup is real: dealer financing often adds 1–2% over what your bank or credit union would offer. Get a pre-approval before visiting the lot — it is your strongest negotiating card.
- The trade-in and the price are separate deals. Negotiate the car's price first, then the trade-in — bundling them hides money.
- Gap between value and debt: with a small down payment and a long term, the car can be worth less than you owe for years.
Disclaimer
Estimates for information only, not financial advice. Actual offers include taxes, fees and insurance that vary by dealer and state.
Frequently asked questions
How is a car payment calculated?
The amount financed (price − down payment − trade-in) is amortized with the standard formula over your term. APR and term length drive the payment: longer terms lower the monthly number but raise total interest.
Is a 72 or 84-month car loan a bad idea?
It is the most expensive way to buy: interest accrues for 6–7 years while the car loses value fastest. Long terms also raise the risk of being "underwater" — owing more than the car is worth. If only a long term makes the payment fit, the honest signal is that the car may be too expensive.
How much should I put down on a car?
A common guideline is 10–20%. A bigger down payment reduces the financed amount, the interest, and the underwater risk — and often unlocks a better rate.
Does this include tax, registration and insurance?
No — this covers the loan itself. Sales tax, registration fees and insurance come on top; dealers sometimes roll tax and fees into the loan, which quietly increases the financed amount. Ask for the out-the-door price.