Auto Loan Calculator

A finance office quotes you a monthly payment. It rarely volunteers the total interest, and those two numbers tell very different stories about the same loan. Stretching $32,000 from 60 months to 84 months cuts the payment by well over $100 and adds thousands of dollars in interest, which is precisely why the longer term tends to be the one offered first.

This calculator works the whole deal out. Enter the vehicle price, your down payment and trade-in, the APR you have been quoted, and your state, and it returns the monthly payment, the amount you are genuinely financing once tax and fees are folded in, the total interest across the life of the loan, and a month-by-month amortization schedule. It also prices the identical loan at 48, 60, and 72 months side by side, so the cost of a longer term stops being an abstraction and becomes a figure you can look at.

Everything recalculates as you type. Nothing is transmitted to a server and no personal information is collected.

How to use this calculator

1. Enter the vehicle price you have actually negotiated, not the sticker or the advertised price. If you are still shopping, use the number you expect to agree on.
2. Select your state. This fills in the vehicle sales or use tax rate automatically. If your county or city adds a local surtax, type the combined rate over the top of it.
3. Add your down payment and trade-in value. Both reduce the amount financed. Use the trade-in figure the dealer has committed to in writing, not an online estimate.
4. Enter the APR. If you have a pre-approval, use that rate. If you do not, pick the row matching your credit score from the table further down this page.
5. Add fees. Documentation, registration, title, and dealer fees are financed along with the vehicle. Leaving them at zero will understate your payment by a few dollars a month.

Then read the term comparison. If the 72-month row saves you $90 a month but costs $2,400 more in interest, that is the trade you are being offered.

How the calculation works

The tool first establishes what you are actually borrowing. Sales tax is applied to the vehicle price, fees are added, and your down payment and trade-in are subtracted:

Amount financed = (Price × (1 + tax rate)) + fees − down payment − trade-in

That figure, not the sticker price, is the principal. It is the single most common reason a dealer quote comes in above a buyer’s own estimate: tax and fees on a $30,000 car in a 6% state add roughly $1,800 before anyone discusses interest.

The payment itself uses the standard amortizing loan formula, where r is the monthly rate (APR divided by 12) and n is the number of months:

Payment = P × [ r(1 + r)ⁿ ] / [ (1 + r)ⁿ − 1 ]

At 0% APR the formula collapses to simple division, and the tool handles that case directly: the principal divided by the number of months.

Auto loans amortize, which means every payment is split between interest and principal, and the ratio shifts over time. Early payments are interest-heavy because interest is charged on a large outstanding balance. By the final year, almost the entire payment is retiring principal. The schedule in the tool shows that split for every single month, which is the clearest way to see why paying a loan off early saves less than most people expect if they wait until year five to do it.

Average auto loan APR by credit score

Credit tier is the single largest lever on what a car costs you. The spread between excellent and deep subprime credit on the same $30,000 loan runs to five figures in total interest over 60 months.

Illustrative averages, last updated September 2026. Rates move with the federal funds rate and vary by lender, term, and vehicle age — treat these as a starting point, not a quote.

Two things worth knowing. Used car rates run consistently higher than new car rates because the collateral depreciates faster and is harder to value. And manufacturer promotional financing, including 0% offers, is typically restricted to the top tier and often replaces a cash rebate, so the promotion is not always the cheaper path. Our guide to 0% financing over 72 months works through when to take the rate and when to take the cash.

Refinancing your car loan

A refinance is the same math as buying, run backwards. Instead of the vehicle price, you start with your current loan balance. Call the lender or check your last statement for the exact payoff figure, not the amount you originally borrowed. Enter that balance as the “price,” set trade-in and fees to zero unless your new lender is charging an origination fee, and put in the new APR you’ve been offered. The calculator gives you the new payment the same way it gives anyone else one.

The number that actually matters is the gap between your new rate and your current one, not the sticker rate itself. A move from 9.5% to 6% on a $22,000 balance with three years left saves real money. A move from 7% to 6.4% on the same balance mostly covers the paperwork and not much else. If the new loan resets the clock to a full 60 or 72 months, you can end up paying more in total interest despite the lower rate, so run both terms side by side in the comparison table above before signing anything.

Refinancing tends to make sense in three situations: your credit score has genuinely improved since you financed the car, national rates have dropped meaningfully, or your original loan came from the dealer’s captive lender at a marked-up rate you didn’t shop around for. It tends not to help if you’re already more than halfway through the term, since most of what’s left is principal rather than interest, or if the car’s value has dropped enough that a new lender won’t approve the loan without a large cash payment toward the balance.

One thing worth checking before you apply: some loans carry a prepayment penalty. It’s rare on auto loans but not unheard of, and it’s listed in your original contract, not your monthly statement.

Paying your loan off early

An amortizing loan is front-loaded with interest, which means an extra payment made in year one does more good than the same extra payment made in year four. In the early months, a large share of what you pay is interest on the full outstanding balance. Every dollar you send beyond the required payment goes straight to principal, and it stops that dollar from generating interest for every remaining month on the loan.

To see the effect on this calculator, treat a planned lump-sum payoff as a shorter term instead of a smaller balance. Take your current payoff figure from your lender, put it in as the price with trade-in and fees at zero, set the APR to what you are actually paying, and try progressively shorter terms until the payment matches what you can realistically send each month. The interest column at each term length is the amount you are saving by finishing early.

One thing worth checking before you throw extra money at a car loan: whether you have higher-interest debt sitting elsewhere, and whether your loan carries a prepayment penalty. Auto loans rarely have one, but it costs a phone call to confirm, and paying down an 8% car loan early is a worse use of money than clearing a 24% credit card balance first.

How much interest you will actually pay

The payment amount hides the interest total, which is exactly the point of quoting it that way. Two loans with the same monthly payment can carry very different total costs once you change the term, and the only way to see it clearly is to look at the total interest figure directly rather than the payment.

As a rough guide, a 60-month loan on a typical new-car balance at a mid-single-digit APR runs total interest somewhere in the low thousands. Stretch the same loan to 72 or 84 months and the total interest climbs by 40% to 70%, even though the APR has not changed at all, because you are paying interest on a large balance for a longer stretch of time. The term comparison built into this calculator runs 48, 60, and 72 months side by side for exactly this reason: it is the fastest way to see what a lower payment is actually buying you, or costing you.

The other lever is the rate itself. A two-point difference in APR sounds small until you apply it across five or six years of an outstanding balance. If your APR is a guess rather than a real pre-approval, treat the interest total this calculator shows you as the low end of a range, not a fixed number.

Frequently asked questions

Can I use this calculator to check if refinancing my car loan is worth it?

Yes. Enter your current payoff balance in place of the vehicle price, leave trade-in and fees at zero unless your new lender charges an origination fee, and enter the new APR you’ve been quoted. Compare the new monthly payment and total interest against what’s left on your current loan. The term length matters as much as the rate: resetting to a longer term can lower your payment while costing more overall, even at a lower APR.

What is a good APR on a car loan?

It depends almost entirely on your credit score, and secondarily on whether the car is new or used. With a score above 720 you should expect something in the mid single digits on a new vehicle. Between 660 and 689 the same loan typically prices in the low double digits. If a dealer quotes you materially above the tier shown in the table on this page, you are being marked up, and a credit union pre-approval is usually the fastest way to fix that.

Should I take a 72 or 84 month loan?

Only if you have run the interest cost and accepted it. Long terms lower the payment and raise the total cost, and they keep you underwater on the loan for longer, meaning you owe more than the car is worth well into year four or five. That matters if the vehicle is totaled or you need to sell. A useful discipline is to choose the shortest term whose payment you can comfortably carry, rather than the longest term you can technically qualify for.

Does my trade-in reduce the sales tax I pay?

In most states, yes. Roughly forty states apply sales tax only to the difference between the purchase price and the trade-in allowance, which can be a meaningful saving. This calculator applies tax to the full vehicle price and then subtracts the trade-in, which is the more conservative treatment. If your state grants a trade-in tax credit, subtract the trade-in value from the vehicle price field and leave the trade-in field at zero to model it accurately.

Is my down payment taxed?

No. Sales tax is assessed on the vehicle price, not on how you choose to pay for it. A larger down payment reduces the amount you finance and therefore the interest you pay, but it does not change the tax owed. That is why the calculator applies tax before subtracting the down payment.

What is not included in this estimate?

Gap insurance, extended warranties, service contracts, paint protection, and any other back-end product the finance office adds. These are frequently rolled into the loan and can add well over a thousand dollars to the amount financed. Insurance premiums, fuel, maintenance, and registration renewals are also excluded, since they are running costs rather than part of the loan. Add any financed add-ons to the fees field to see their true cost over the term.

How much car can I actually afford?

A widely used rule of thumb is 20/4/10: at least 20% down, a term no longer than four years, and total monthly vehicle costs including insurance and fuel below 10% of gross monthly income. It is deliberately conservative and many buyers cannot meet it, but it is a useful reference point. If you would rather work backwards from a payment you know you can afford, our car payment calculator is built for exactly that.

Does applying for a car loan hurt my credit score?

A single application produces a hard inquiry worth a few points, which recovers within months. Rate shopping is protected: the major scoring models treat multiple auto loan inquiries inside a short window, typically 14 to 45 days depending on the model, as one inquiry. Getting quotes from several lenders in the same fortnight therefore costs you roughly the same as getting one.

Why is the dealer’s quote higher than this calculator says?

Usually one of four reasons. Fees were not entered here, back-end products were added to the contract, the APR quoted to you is higher than the one you entered, or the term is longer than you assumed. Ask for the amount financed and the APR in writing, put both into this calculator, and any remaining difference is something the finance office needs to account for.

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