Auto Loan Calculator: Estimate Payment, Taxes, Fees & Total Cost
Estimate your real car payment, not just a teaser number. This auto loan calculator builds the amount financed from vehicle price, sales tax, title, registration and dealer fees, your down payment, a trade-in (including any negative equity), and cash rebates — then shows the monthly payment, total interest, and the full cost of the deal.
Adjust the inputs and select Calculate for a full breakdown.
Year-by-year amortization of the amount financed
Compare Common Scenarios
How the numbers shift across typical situations for this calculator:
| Scenario | Monthly payment | Amount financed | Total interest | Total of payments |
|---|---|---|---|---|
| Base · $40k · 7% · 60 mo | $762.35 | $38,500.00 | $7,240.77 | $45,740.77 |
| Long-term · $40k · 7% · 84 mo | $581.07 | $38,500.00 | $10,309.73 | $48,809.73 |
| Bigger down payment · $12k down | $623.74 | $31,500.00 | $5,924.27 | $37,424.27 |
| Negative equity trade-in | $576.02 | $32,400.00 | $9,073.42 | $41,473.42 |
| Cash rebate · $2.5k at 7% APR | $712.84 | $36,000.00 | $6,770.59 | $42,770.59 |
| Promo APR · no rebate · 2.9% APR | $690.09 | $38,500.00 | $2,905.10 | $41,405.10 |
How This Calculator Works
Enter the vehicle price and the deal details. The calculator computes sales tax as price × rate, adds title, registration and dealer fees, and subtracts your down payment, trade-in value and cash rebate. Any balance still owed on the trade-in is added back as negative equity. Taxes and fees you pay upfront stay out of the loan; the rest is rolled into the amount financed. The APR is converted to a monthly rate, and the fixed-rate PMT formula produces a constant monthly payment over the term you choose. A year-by-year schedule then splits each year into principal and interest.
The Formula
Auto Loan Payment (PMT) on the Amount Financed
A = amount financed = vehicle price + financed taxes/fees + amount owed on trade-in − down payment − trade-in value − cash rebate; r = monthly decimal rate = APR ÷ 100 ÷ 12; n = term in months.
Worked Example
Suppose a $40,000 car with 7% sales tax ($2,800), $400 title/registration and a $300 dealer doc fee, with $5,000 down and no trade-in. Tax and fees total $3,500; with nothing paid upfront, all of it rolls into the loan. The amount financed is $40,000 + $3,500 − $5,000 = $38,500. At 7% APR over 60 months the payment is about $762.35, you pay roughly $7,240.77 in interest, and the loan side of the deal totals about $45,740.77 — on top of the $5,000 you put down at signing.
Key Insight
Two numbers decide whether a car is affordable, and neither is the monthly payment: the amount financed and the total interest. Rolling tax, fees and negative equity into the loan and stretching the term to 72 or 84 months makes the monthly figure look easy while quietly adding thousands in interest and keeping you underwater for years.
What this auto loan calculator includes
Most quick payment tools ask only for a loan amount, rate and term. A real car deal has more moving parts, and this calculator models them: the vehicle price, sales tax (price × your rate), title and registration, the dealer documentation fee, any other financed add-ons, your cash down payment, a trade-in and what you still owe on it, and manufacturer cash rebates.
Crucially, it separates taxes and fees you pay upfront from those you roll into the loan. Upfront tax and fees raise the cash you bring to signing but stay out of the financed balance; rolled-in tax and fees increase the amount financed and the interest. The result is an amount financed that matches what your lender will actually book, so the monthly payment, total interest and total cost reflect the real deal rather than a stripped-down estimate.
60 vs 72 vs 84 months — the term trap
Dealers love to quote a longer term because it shrinks the monthly payment, but the same loan costs far more interest the longer it runs. Using this calculator's formula on $40,000 financed at 7% APR: 36 months is about $1,235/month with roughly $4,463 in interest; 60 months is about $792/month and $7,523; 72 months is about $682/month and $9,101; 84 months is about $604/month and $10,711.
Stretching from 36 to 84 months cuts the payment by roughly half but more than doubles the interest — about $6,200 more for the same car. Longer terms also keep you underwater longer, because a new car can lose a large share of its value in the first few years while the balance falls slowly. As a rule of thumb, 60 months is a sensible ceiling for a new car and 48 for an older used one; if you need 72 or 84 months to afford the payment, it is usually a sign to look at a cheaper car.
Trade-ins and negative equity
A trade-in works like extra down payment: the dealer's allowance is subtracted from the amount financed. If your trade is worth $8,000 and you owe nothing on it, that is an $8,000 reduction in what you finance — straightforward equity working in your favor.
Negative equity flips that. If the dealer values your trade at $8,000 but you still owe $12,000, the $4,000 shortfall does not disappear — it is rolled into the new loan. You then finance the new car's cost plus that old $4,000, and pay interest on both. Enter both the trade-in value and the amount owed so the calculator captures this. Rolling negative equity forward is one of the fastest ways to stay perpetually upside down across several cars.
Rebate vs low APR: compare total cost
Manufacturers often make you choose between a cash rebate and a promotional low (or 0%) APR. They are not interchangeable, and the cheaper option depends on the loan size and term. A rebate lowers the amount financed immediately; a low APR keeps the full price but charges less interest over time.
The honest way to decide is to compute both, and the scenario table above does exactly that with two side-by-side rows: 'Cash rebate · $2.5k at 7% APR' takes the cash and finances less at the standard rate, while 'Promo APR · no rebate · 2.9% APR' keeps the full price but charges far less interest. Compare their amount financed and total interest directly. On smaller or shorter loans the rebate often wins; on larger or longer loans a deep APR cut can pull ahead. Decide on total cost — amount financed plus total interest — not on the monthly payment alone.
Taxes, title, registration and dealer fees
The sticker price is rarely what you finance. Sales tax is applied to the vehicle price at your combined state and local rate, which varies by location. Using this calculator's formula, a 7% rate on a $40,000 car adds $2,800, and title, registration and a dealer doc fee add more on top.
These charges are part of the cost of the car whether you pay them at signing or finance them. Paying tax and fees upfront keeps the loan smaller and saves interest, but raises the cash you need at delivery. This calculator lets you split them: enter the amount of tax and fees you pay upfront, and the remainder is rolled into the amount financed. Watch the dealer doc fee in particular — it varies a lot and is sometimes negotiable or capped by state law.
Total cost of ownership: payment is only one part
The monthly payment is the most visible cost of a car but far from the only one. Insurance, fuel or electricity, maintenance and repairs, registration renewals, and above all depreciation add up to thousands of dollars a year on top of the loan. AAA's annual Your Driving Costs study tracks these full ownership costs and is worth consulting before you commit.
Treat the payment this calculator produces as the financing piece of a larger budget. A loan you can technically afford can still be a stretch once insurance and fuel are added, especially on a longer term where you owe more than the car is worth. Sizing the payment so total ownership costs stay a comfortable share of your income — and choosing a term you can pay off well before the car wears out — is what keeps a car from becoming a financial drag.
Monthly payment and total interest by loan term ($40,000 financed at 7% APR)
The same $40,000 financed at the same rate over different terms, computed with this calculator's formula. Longer terms shrink the payment but multiply total interest — and keep you underwater longer.
| Term | Monthly payment | Total interest | Total of payments |
|---|---|---|---|
| 36 months (3 yr) | $1,235 | $4,463 | $44,463 |
| 48 months (4 yr) | $958 | $5,977 | $45,977 |
| 60 months (5 yr) | $792 | $7,523 | $47,523 |
| 72 months (6 yr) | $682 | $9,101 | $49,101 |
| 84 months (7 yr) | $604 | $10,711 | $50,711 |
Figures rounded to the nearest dollar. The lowest monthly payment costs the most over the life of the loan. A sensible ceiling is 60 months for a new car and 48 for an older used one.
Where to finance: preapproval vs dealer vs promo APR vs rebate
Four common ways to fund a car purchase, and how each maps to the inputs above. Compare total interest, not just the monthly payment.
| Aspect | Best for | Watch out for | What to compare | Calculator input to change |
|---|---|---|---|---|
| Bank / credit-union preapproval | Most buyers who want a rate locked before negotiating | Rate offer can expire; may not include dealer incentives | APR and total interest vs the dealer's quote | Set Interest rate (APR) to your preapproved rate |
| Dealer / captive financing | Convenience and access to manufacturer promos | Marked-up APR and longer terms that hide the true cost | The dealer APR and term against your preapproval | Enter the dealer's APR and term and compare totals |
| Manufacturer promo APR (low-rate offer) | Larger or longer loans where low interest saves the most | Usually cannot be combined with the cash rebate | Total of payments at the promo APR, full price | Lower the APR, keep the rebate at $0 |
| Manufacturer cash rebate | Smaller or shorter loans, or paying mostly in cash | Giving up a deep promotional APR to take the cash | Total of payments with the rebate at standard APR | Enter the rebate, use the standard market APR |
Frequently Asked Questions
Is sales tax included in the car payment?
It can be. This calculator computes sales tax as the vehicle price times your state and local rate, then lets you either pay it upfront in cash or roll it into the loan. Financing the tax raises the amount financed and the interest you pay.
What are dealer documentation (doc) fees?
A doc fee is what the dealer charges to process paperwork on the sale. It is sometimes negotiable and is capped by law in some states. Enter it in the dealer doc fee field; like tax, you can finance it or pay it upfront.
What about title and registration fees?
Title, registration and plate fees are charged by your state DMV and vary widely. Put them in the title and registration field. They are part of the cost of the deal whether you pay them at signing or roll them into the loan.
Does a bigger down payment lower my payment?
Yes. A larger down payment reduces the amount financed dollar-for-dollar, which lowers both the monthly payment and the total interest over the life of the loan. It also reduces the risk of being underwater early on.
How does a trade-in affect the loan?
Your trade-in value works like extra down payment: it is subtracted from the amount financed. Enter the dealer's trade allowance in the trade-in value field. If you still owe money on that car, also fill in the amount owed.
What is the amount owed on a trade-in?
It is the loan balance remaining on the car you trade in. If you owe less than the trade is worth, you keep the difference as equity. If you owe more, the gap is negative equity and gets added to your new loan.
What is negative equity, or being upside down?
You are upside down when you owe more on a vehicle than it is worth. When you trade in a car with negative equity, that shortfall is rolled into the new loan, so you finance more than the new car costs and pay interest on the old debt too.
Should I take a manufacturer rebate or a low-APR offer?
Run it both ways. A cash rebate lowers the amount financed at the standard rate; a promotional low APR keeps the full price but charges less interest. Enter the rebate at the normal rate, then the full price at the promo rate, and pick the lower total cost.
What is a good APR on a car loan?
It depends on your credit and whether the car is new or used; new-car rates are usually lower than used. Check the Federal Reserve G.19 averages cited on this page as a benchmark, and always compare a bank or credit-union preapproval against the dealer's offer.
Are 72- or 84-month auto loans a good idea?
They lower the monthly payment but raise total interest and keep you underwater far longer, because the car depreciates faster than the balance falls. They make sense only if you keep the car well past payoff. For most buyers, 48–60 months is the safer ceiling.
Should I get preapproved before going to the dealer?
Usually yes. A bank or credit-union preapproval gives you a real rate to negotiate against, so the dealer has to beat it rather than mark up the financing. Compare the APR and total interest, not just the monthly payment.
Can I refinance an auto loan later?
Often, yes. If rates fall or your credit improves, refinancing to a lower APR or shorter term can cut total interest. It works best early in the loan, before too much interest is paid and while the car still has enough value relative to the balance.
References & Authoritative Sources
- CFPB — Consumer Financial Protection Bureau — Auto loan guide and dealer financing · consulted June 27, 2026 · Federal consumer protection — auto loan APR, dealer markups, add-ons and total cost disclosure
- AAA — Your Driving Costs Annual Report — Total cost of vehicle ownership benchmark · consulted June 27, 2026 · Annual benchmark — full ownership cost beyond the loan payment (insurance, fuel, depreciation)
- Federal Reserve — Consumer Credit (G.19) — Auto loan interest rate statistics · consulted June 27, 2026 · Authoritative source — current US auto loan APR averages by lender type and maturity
Related Calculators
Data Sources & Benchmarks
This calculator draws on 2 independent, dated sources.
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Methodology & Review
The monthly payment uses the standard fixed-rate PMT formula M = A·r/(1−(1+r)^−n) on the amount financed. The amount financed is built from vehicle price plus sales tax (price × rate) and title, registration and dealer fees, minus down payment, trade-in value and cash rebate. Taxes and fees you pay upfront are excluded from the loan; the rest is rolled in. Negative equity (amount owed on a trade-in above its value) is added to the amount financed. For a rate reference, the Federal Reserve G.19 series puts the average 48-month new-car loan rate near 7.36% (Feb 2026), with an average amount financed around $42,500 over a roughly 66-month term (finance-company data, March 2026). A year-by-year amortization schedule splits each payment into principal and interest, and every published figure is locked by golden tests that run on each build.
Reviewed according to the CalcDomain Editorial Policy & Calculator Methodology. We document formulas, edge cases, sources, update dates, and correction paths for calculator pages.
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