Auto Loan Calculator 2026

How Auto Loans Are Structured and What Borrowers Should Know

An auto loan is a secured installment loan, meaning the vehicle you purchase serves as collateral for the debt. If you stop making payments, the lender has the legal right to repossess the car. This collateral arrangement is the reason auto loan interest rates tend to be lower than unsecured personal loan rates, because the lender faces less risk. When you sign an auto loan agreement, you agree to a fixed monthly payment over a set number of months, and the lender holds the title to the vehicle until the loan is paid in full.

Like any amortized loan, your auto loan payment is divided between interest and principal. In the early months, a larger portion of each payment goes toward interest, and as the balance decreases over time, more of each payment is applied to principal. The key difference with auto loans compared to other types of borrowing is that the asset securing the loan depreciates rapidly. A new car loses roughly 20% of its value in the first year and about 15% per year for the next several years. This depreciation dynamic creates a unique set of financial risks that borrowers need to understand before signing at the dealership.

The total cost of an auto loan includes not just the principal and interest but also sales tax, registration fees, dealer documentation fees, and any add-on products like extended warranties or gap insurance. Many buyers focus exclusively on the monthly payment during negotiations, which allows dealers to obscure the total cost by extending the loan term or adjusting other variables. The calculator on this page helps you see the complete picture so you can negotiate from a position of knowledge rather than vulnerability.

Dealer Financing Versus Bank and Credit Union Loans

When you buy a car from a dealership, the finance manager will almost certainly offer to arrange financing for you. Dealer financing is convenient because it allows you to handle the purchase and the loan in one place, but convenience comes at a cost. Dealerships operate as intermediaries between you and the actual lender, and they earn a commission, known as the dealer markup or reserve, by adding a percentage to the rate the lender offers. A bank might approve you at 5.5%, but the dealer could present the loan at 7%, pocketing the difference as profit. You would never know this happened unless you had already secured your own pre-approval before walking into the dealership.

Credit unions are consistently among the best sources of auto loan financing. As member-owned nonprofits, credit unions typically offer rates one to two percentage points below bank and dealer rates. Many credit unions also impose maximum loan-to-value ratios and term limits that protect borrowers from overextending themselves. If you are not already a member of a credit union, most are easy to join. Many accept members based on geographic area, employer, or even membership in a qualifying organization that costs a few dollars to join. The savings over the life of an auto loan can easily amount to $1,000 to $3,000 compared to dealer financing.

The smartest approach is to get pre-approved by your bank or credit union before visiting any dealership. A pre-approval letter tells you exactly what rate and loan amount you qualify for, giving you a benchmark against which to evaluate any dealer financing offer. In some cases, dealer promotions, particularly manufacturer-subsidized 0% or low-rate financing on new models, will beat your pre-approval. When that happens, take the dealer offer. But without a pre-approval in hand, you have no way to know whether the dealer is offering a competitive rate or padding their profit margin at your expense.

The Impact of Loan Term on Total Cost: 36 Versus 60 Versus 72 Months

The average auto loan term in the United States has stretched to nearly 70 months for new cars and 65 months for used cars, according to Experian data. This trend toward longer loans has been driven by rising vehicle prices and the desire to keep monthly payments within reach. However, longer terms cost borrowers far more in total interest and dramatically increase the risk of negative equity.

Consider a $35,000 vehicle financed at 6.5% interest. With a 36-month term, the monthly payment is roughly $1,072, and the total interest paid is approximately $3,586. Extend the term to 60 months and the payment drops to $685, but the total interest climbs to $6,079. At 72 months, the payment falls to $590 but the total interest reaches $7,476. That is nearly $4,000 more in interest for the 72-month loan compared to the 36-month option. The borrower choosing the longest term pays an extra $3,890 purely for the convenience of a lower monthly payment.

Beyond interest costs, longer terms also mean higher risk of being underwater on the loan. Because cars depreciate rapidly in the first few years, a borrower with a 72-month loan may owe more than the car is worth for the first three to four years of ownership. If the vehicle is totaled in an accident or the borrower needs to sell or trade it during that period, they face a shortfall that must be paid out of pocket. A 36 or 48-month term, combined with a reasonable down payment, greatly reduces this risk. Our calculator above shows you exact numbers for any combination of price, rate, and term so you can find the sweet spot between affordable payments and manageable total cost.

New Car Versus Used Car Financing

The decision between financing a new or used vehicle involves more than just the sticker price. Interest rates on used car loans are typically one to two percentage points higher than rates on new cars. Lenders charge more for used car loans because the collateral, the vehicle, is older and worth less, meaning the lender recovers less if they have to repossess and sell it. Additionally, used car loan terms are sometimes shorter than new car terms, which pushes monthly payments higher.

From a total cost perspective, buying a used car that is two to three years old is almost always the more financially sound decision. A car that originally cost $40,000 might sell for $28,000 at two years old, representing a $12,000 savings even before financing costs. Even with a higher interest rate on the used car loan, the lower purchase price means the total amount of interest paid is typically less than it would be on a new car loan for the higher amount. The heaviest depreciation occurs in the first two years, so the used car buyer avoids the steepest portion of the depreciation curve while still getting a relatively modern vehicle with most of its useful life remaining.

Certified pre-owned (CPO) programs occupy a middle ground. These vehicles have been inspected and reconditioned by the manufacturer's dealer network, and they come with an extended warranty that provides some of the peace of mind associated with buying new. Financing rates on CPO vehicles are sometimes comparable to new car rates, particularly during manufacturer promotional periods. If you value reliability assurance but want to avoid the full depreciation hit of a new purchase, a CPO vehicle financed at a competitive rate can be an excellent compromise.

The Gap Between Sticker Price and Out-the-Door Price

One of the most common surprises for car buyers is the difference between the advertised price of a vehicle and the amount they actually finance. The sticker price, also called the manufacturer's suggested retail price (MSRP) for new cars or the asking price for used cars, does not include several additional costs that get rolled into your loan. Sales tax alone can add 5% to 10% depending on your state, which means a $35,000 car in a state with 8% sales tax requires financing an additional $2,800 just for the tax. Registration and title fees add another few hundred dollars. Dealer documentation fees, which vary by state but often range from $200 to $800, are another line item that increases the financed amount.

If you purchase an extended warranty, paint protection, fabric treatment, or any other dealer add-on, those costs are also typically rolled into the loan. These products are almost always overpriced compared to purchasing them independently, and they increase your monthly payment and total interest for the entire term of the loan. A $2,000 extended warranty financed at 7% over 60 months adds roughly $40 to your monthly payment and costs about $2,376 in total, meaning you pay $376 in interest on a product that may never pay out. This is why financial advisors consistently recommend declining dealer add-ons or, at minimum, negotiating them separately from the vehicle price.

When using this calculator, enter the full out-the-door price rather than just the sticker price. This gives you an accurate picture of your actual monthly payment and total cost. Ask the dealer for an itemized breakdown of every charge included in the total price before agreeing to financing terms. The more transparent the numbers, the better positioned you are to make a decision that serves your financial interests rather than the dealer's profit margin.

Understanding Negative Equity and Being Underwater

Negative equity, often described as being "underwater" or "upside down" on a loan, occurs when you owe more on your auto loan than the vehicle is currently worth. This situation is more common than most people realize. According to Edmunds, roughly one in four car trade-ins involves negative equity, with the average amount of negative equity exceeding $6,000. This happens because vehicles depreciate faster than most loan balances decrease, particularly during the first two to three years and especially on longer-term loans.

Negative equity becomes a tangible financial problem in several scenarios. If your car is totaled in an accident, your insurance company pays the current market value of the vehicle, not your loan balance. If you owe $28,000 and the car is worth $22,000, you are responsible for the $6,000 difference. Gap insurance, which covers this shortfall, is one of the few dealer add-on products worth considering if you are financing a large percentage of the vehicle's value. If you want to sell or trade in the car while underwater, you must either pay the difference in cash or roll the negative equity into your next auto loan, which puts you in an even deeper hole on the new vehicle.

The best way to avoid negative equity is to make a substantial down payment, choose a shorter loan term, and avoid financing dealer add-ons that inflate the loan amount beyond the car's value. A 20% down payment on a new car nearly eliminates the risk of negative equity from the start, because even after the first year's depreciation, the car's value is likely to exceed the remaining loan balance. If you are already underwater, the most prudent course is to continue making payments and driving the car until the equity position reverses, which happens naturally as the loan balance decreases through regular amortization.

Refinancing an Auto Loan

If your credit score has improved since you originally financed your vehicle, or if interest rates have dropped, refinancing your auto loan can save you a significant amount of money. The process involves taking out a new loan at a lower rate to pay off the existing loan. The new lender pays off your old lender, and you begin making payments to the new lender at the reduced rate. Refinancing typically involves no out-of-pocket costs, though some lenders charge a small application or origination fee.

The savings from refinancing depend on the rate reduction, remaining balance, and remaining term. Reducing the rate on a $22,000 balance from 8% to 5% with 48 months remaining saves approximately $1,600 in interest over the remaining life of the loan. If you refinance and keep the same payoff date, your monthly payment decreases. Alternatively, you can maintain a similar monthly payment and shorten the term, paying off the car sooner while still saving on interest.

Not every situation warrants refinancing. If you are close to the end of your loan, the remaining interest savings may be too small to justify the effort. Similarly, if your car is very old or has high mileage, some lenders may not approve a refinance because the collateral value is too low. The sweet spot for auto loan refinancing is typically within the first two to three years of the loan, when the remaining balance is still substantial enough for a lower rate to produce meaningful savings. Use this calculator to compare your current loan terms against potential refinancing offers to determine whether the switch makes financial sense for your situation.

How Your Down Payment Affects Monthly Payments and Total Cost

The size of your down payment directly influences every aspect of your auto loan. A larger down payment reduces the amount you need to finance, which lowers your monthly payment, decreases the total interest paid, and reduces the risk of negative equity. Financial experts generally recommend putting at least 20% down on a new car and at least 10% down on a used car, though many buyers finance with far less.

On a $32,000 vehicle financed at 6% for 60 months, putting zero down results in a monthly payment of approximately $619 and total interest of about $5,099. A $6,400 down payment (20%) reduces the financed amount to $25,600, dropping the monthly payment to $495 and total interest to $4,079. The down payment saves $1,020 in interest and provides an immediate equity cushion that protects against being underwater. If you combine a trade-in with a cash down payment, the effect is even more pronounced. Our calculator lets you enter both a down payment and trade-in value separately to see how each component affects your financing.

Saving for a larger down payment also signals financial discipline to lenders, which can result in a better interest rate. A buyer who puts 20% down is viewed as lower risk than one who finances the entire purchase, and that risk assessment often translates directly into a rate reduction. Even a half-point rate improvement on a five-year loan can save several hundred dollars in interest. Taking three to six months to save up a larger down payment before purchasing a vehicle is one of the simplest ways to reduce both your monthly obligation and the total cost of vehicle ownership. Consider using our savings calculator to set a down payment savings goal and track your progress toward it.