How a Car Loan Works: APR, Term & Total Cost Explained

At the dealership, the salesperson asks one question over and over: "What monthly payment are you comfortable with?" It sounds friendly. It is also the question that costs buyers the most money, because a payment can be made to look small by stretching the loan out. The number that really matters is what the whole loan costs.

This guide explains how a car loan works in plain words, what drives the cost, and how to arrive at the dealership with a plan.

The quick answer

• A car loan lets you pay for a car over time. You pay back the amount you borrowed (the principal) plus interest.
• APR is the yearly cost of the loan, as a percent. Your credit score has the biggest effect on it.
• Loan term is how many months you take to pay. A longer term gives a lower payment but a higher total cost.
• Get a pre-approval from a bank or credit union before you shop. It becomes your bargaining chip.

How a car loan works

When you finance a car, a lender pays the seller, and you pay the lender back in equal monthly payments. Each payment has two parts: interest (the lender's fee) and principal (the part that reduces what you owe). Most car loans use simple interest. Interest is worked out each month on the balance you still owe, so as the balance drops, the interest part of the payment gets smaller and the principal part gets bigger.

The car is also the lender's safety net. It is called collateral. If you stop paying, the lender can take the car back.

What does a typical car loan look like in 2026?

According to Experian's numbers for the second quarter of 2026, the average new car loan was about $43,600, at an average rate of 6.35%, over about 69 months, with a payment near $765 a month. The average used car loan was about $27,900, at an average rate of 11.19%, over about 68 months, with a payment near $542 a month. These are averages across all buyers, and your own numbers can be very different, mostly because of your credit.

APR vs interest rate

The interest rate is the price of borrowing money. The APR (annual percentage rate) is the interest rate plus certain fees, expressed as a yearly rate. When you compare offers, compare the APR, because it shows the more complete cost.

What decides your APR?

• Your credit score. This is the big one. Look at the table below.
• The loan term. A lender may charge a different rate for a longer loan, so compare the same term across offers.
• New or used. Used cars generally cost more to finance.
• Your down payment. A bigger one means less risk for the lender.
• Your income and other debts.

Here is what credit score did to average rates in the second quarter of 2026, according to Experian, which groups borrowers by VantageScore 4.0 tiers:

What does that mean in dollars? Say you finance $32,100 for 60 months. At the super prime rate, you pay about $3,700 in interest. At the near prime rate, you pay about $8,500. At the deep subprime rate, about $14,800. Same car, same loan length, a $11,000 gap, just from the credit tier.

The loan term trap

Here is a real example. A car costs $35,000. You put $5,000 down, and 6% sales tax brings the amount you finance to about $32,100. At a 7% APR:

Going from 48 months to 84 months drops the payment by $285 a month. But it adds $3,800 in interest, and you are in debt for three more years. Our auto loan calculator lets you add your own price, down payment, trade-in and tax, and compare terms side by side.

Why long loans are risky: negative equity

New cars lose value fast. If your loan is long and your down payment is small, you can end up owing more than the car is worth. This is called negative equity, or being "upside down".

Look at the $35,000 car again. Say it loses 20% of its value in the first year, which is an assumption for this example (the real drop depends on the model). It is then worth about $28,000. On the 84-month loan, you would still owe about $28,400, so you owe more than the car is worth. On the 60-month loan, you would owe about $26,500, so you are fine. If the car is totaled or you need to sell it, being upside down means paying out of your own pocket.

How much car can you afford?

A popular rule of thumb, which is not an official standard, is the 20/4/10 rule:

• 20% down payment
• Loan of no more than 4 years (48 months)
• Total car costs (payment, insurance, fuel) of no more than 10% of your gross income

It is a guideline, not a law. In a high-price market, many people cannot hit all three, and that is okay. But if you break the rule, break it on purpose, and know the cost.

Get pre-approved before you shop

A pre-approval is a loan offer from a bank, credit union or online lender, issued before you pick a car. It shows you a real rate, and gives you something to compare against the dealer's offer. Check credit unions as well as banks. The CFPB advises keeping your loan applications within 14 to 45 days of each other, so that they are counted as only one credit inquiry. That way, shopping around does not pile up several hits on your score.

Watch out for add-ons and tricks

• Payment packing. Optional extras like service plans or paint protection can be rolled into the loan, so the payment goes up without the price being clear. Ask for the "out-the-door price".
• Rate markups. The CFPB explains that the rate a dealer offers is the lender's "buy rate" plus additional interest that pays the dealer for arranging the loan. Ask what the buy rate is, and compare the offer with your pre-approval.
• Extended warranties and GAP insurance. The CFPB says add-ons like these are generally optional, that a lender or dealer cannot require them unless the contract says so, and that your own insurer may offer similar coverage. Financing them adds to your loan and to the interest you pay.
• Long terms to hit a payment. If you hear "we can get you to $450 a month", ask how many months that takes.

A simple way to negotiate

1. Settle the price of the car first, separate from financing and your trade-in.
2. Ask for the out-the-door price in writing, including tax and fees.
3. Bring your pre-approval and ask if the dealer can beat it.
4. Read the contract: APR, term, amount financed and total of payments.
5. Decline add-ons you do not understand. You can always say you will think about it.

Can you pay off a car loan early?

Usually yes. With a simple interest loan, extra money goes to principal and saves interest. On the example above (60 months at 7%), an extra $100 a month would end the loan in 51 months instead of 60, and save about $1,000. First check that your loan has no prepayment penalty, and tell the lender to apply extra payments to the principal. If you have other debts, use the debt payoff calculator to see where extra dollars work hardest.

Can you deduct car loan interest on your taxes?

For some buyers, yes, for the first time in years. A 2025 law created a deduction of up to $10,000 a year for interest on a loan taken out after December 31, 2024, for a new, personal-use vehicle that had its final assembly in the United States. It applies to interest paid in 2025 through 2028, and it phases out for modified adjusted gross income over $100,000 ($200,000 for joint filers), according to the IRS. Used vehicles and lease payments do not qualify. Read the IRS rules, or ask a tax preparer, before you count on it.

Frequently asked questions

How long should a car loan be?

As short as you can comfortably afford. Four to five years (48 to 60 months) is a good target. Longer loans lower the payment but raise the total cost and the risk of owing more than the car is worth.

Is a 72-month car loan bad?

It is not illegal or unusual, but it costs more and keeps you in debt longer. On a $32,100 loan at 7%, 72 months costs about $1,270 more in interest than 60 months. Think hard before choosing it, and make a bigger down payment if you can.

Can I refinance a car loan?

Yes. If your credit has improved or rates have dropped, you can replace your loan with a new one at a lower rate. Check for fees, and make sure you are not extending the term so far that you pay more overall.

How much should a car payment be?

The 20/4/10 rule of thumb above says your total car costs, including insurance and fuel, should stay under 10% of your gross income. Use that as a starting point. A lower payment leaves more room for the rest of your budget.

Does a bigger down payment lower my interest rate?

Often it does, because the lender takes less risk. It also reduces the interest you pay in total, and protects you from negative equity.

The bottom line

The cheapest car loan is not the one with the smallest monthly payment. It is the one with the lowest total cost for a term you can handle. Know your credit tier, get pre-approved, keep the term short, and negotiate the price before the financing. For official guidance on shopping for auto loans and your rights, see the Consumer Financial Protection Bureau's auto loan guide.

Sources

• State of the Automotive Finance Market, Q2 2026 (PDF report), Experian Automotive
• Experian sees refinancing continue to ripen in Q2 (August 27, 2026), Auto Remarketing
• What is the difference between dealer-arranged and bank financing?, Consumer Financial Protection Bureau
• What should I know before I shop for an auto loan at a bank, credit union, dealership or other lender?, Consumer Financial Protection Bureau
• Am I required to purchase an extended warranty, GAP insurance, or credit insurance from a lender or dealer to get an auto loan?, Consumer Financial Protection Bureau
• Auto loans, Consumer Financial Protection Bureau
• One, Big, Beautiful Bill Act: tax deductions for working Americans and seniors (qualified passenger vehicle loan interest), Internal Revenue Service

Loan examples are calculated by script with the standard fixed-rate loan formula, without taxes or fees beyond those stated. Averages change every quarter, and your own offer will differ. Last reviewed October 13, 2026.