Car Payment Calculator

Overview

How to use this calculator

1. Enter the vehicle price you expect to pay. This can be the MSRP, the out-the-door negotiated price before tax, or your working estimate including optional add-ons.
2. Enter your planned down payment and any trade-in value the dealer will credit toward the purchase. If you have negative equity in your current vehicle, increase the vehicle price instead of entering a positive trade value.
3. Enter your local sales tax rate as a percentage. If your state taxes only part of the transaction or nets out the trade differently, adjust the rate or price to approximate your actual taxable amount.
4. Enter the interest rate (APR) you expect from the lender and the auto loan term in months—for example, 36, 48, 60, 72, or 84 months.
5. Review the resulting financed amount (implicit in the calculation), the monthly payment, and the total paid over the full term.
6. Experiment with different down payments, trade values, rates, and terms to see how each lever affects your payment and lifetime cost, then choose a combination that fits your budget and risk comfort.

Inputs explained

Vehicle price

The sticker price or negotiated purchase price of the vehicle before tax. For a more conservative estimate, add dealer fees, aftermarket add-ons, and any negative equity you are rolling in so the price reflects the full amount you are effectively financing.

Down payment

Cash you plan to pay up front at signing. Larger down payments reduce the amount financed, lower your monthly payment, and may reduce total interest paid and insurance costs.

Trade-in value

The value of your current vehicle that the dealer will apply toward your new purchase. This reduces the amount you need to finance. If you owe more on your current vehicle than it’s worth, treat the shortfall as additional cost added to the vehicle price instead of a positive trade value.

Sales tax %

Your local sales tax rate on vehicles expressed as a percentage. Some states tax the full price, some tax price minus trade, and others have special caps or exemptions, so treat this as an approximation unless you know your exact taxable base.

Interest rate (APR)

The annual percentage rate on the auto loan. This includes the base rate and any built‑in lender margin but does not include separate fees. Even a small change in APR can add or remove hundreds or thousands of dollars of interest over a long term.

Term (months)

The length of the loan in months—the number of monthly payments you will make. Common terms range from 36 to 84 months; longer terms lower your monthly payment but increase total interest paid and may keep you underwater on the loan longer.

When to use it

• Comparing dealer, bank, and credit union offers at different APRs and terms to see which combination works best for your budget.
• Testing how a larger down payment, higher trade value, or slightly cheaper vehicle brings the payment into a comfortable range.
• Checking whether stretching the term from, say, 60 to 72 or 84 months actually makes sense once you see the extra interest paid.
• Evaluating whether it is worth rolling negative equity from your current car into a new loan versus driving the existing car longer.
• Setting a maximum vehicle price before you visit the dealership so you can negotiate confidently within a monthly payment target.

Tips & cautions

• Run at least two scenarios: one with the dealer’s suggested term and one with a shorter term to see how much interest the shorter loan saves you.
• If you are payment‑sensitive, start from the maximum monthly payment you are comfortable with and adjust price, down payment, and term until the calculator hits that target.
• Include negative equity and dealer fees in the vehicle price so your monthly payment estimate isn’t artificially low compared to the real offer.
• Compare pre‑approved offers from your bank or credit union using the same inputs; sometimes a slightly lower APR or shorter term has a bigger impact than a small discount on sticker price.
• Remember that insurance, fuel, maintenance, and registration all add to your real monthly cost of owning the car—this calculator focuses on the loan portion only.
• Registration fees, documentation fees, extended warranties, and add‑ons are not included unless you add them into the vehicle price or tax assumptions yourself.
• Assumes a fixed‑rate, fully amortizing loan with regular monthly payments and no late fees, balloon payments, or deferred payment promotions.
• Sales tax handling is simplified and may not match your state’s exact rules, especially where trade‑ins, rebates, or caps are treated differently for tax purposes.
• Does not model additional products like gap coverage, tire and wheel plans, or service contracts, which can add to your monthly payment when financed.
• This is not a credit approval tool and does not consider your credit score, debt-to-income ratio, or lender underwriting rules.

Worked examples

Deep dive

FAQs

Does this include registration or dealer fees?

No. Add them to the vehicle price before running the calculation, or include them as part of the sales tax percentage.

Can I compare multiple terms?

Yes. Adjust the term input to 36, 48, 60, or 72 months to see how payments change.

How do I account for negative equity?

If you owe more on your current vehicle than it is worth, treat the difference as extra cost added to the vehicle price instead of a positive trade value. That way the loan amount and payment reflect rolling that balance into the new loan.

Is this the exact payment the dealer will offer?

Not necessarily. Dealers may include additional fees, promotional structures, or different tax treatments. Use this as a benchmark and compare it with the official payment shown in your financing offer.

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