Auto Loan Calculator

The loan term is the most impactful variable in your total financing cost, and the trend toward longer terms is one of the most financially damaging shifts in consumer auto lending. In 2010, the average auto loan term was around 60 months. Today, 72- and 84-month loans are common, with some lenders offering 96-month (8-year) terms. The monthly payment looks lower — a $35,000 loan at 6% costs $580/month over 60 months versus $504/month over 72 months. But the 72-month loan costs an extra $1,400 in interest and, more importantly, keeps you underwater (owing more than the car is worth) for a much longer period.

Rapid depreciation is the core risk of long-term auto loans. A new car typically loses 20–25% of its value in the first year and 40–50% within three years. On a $40,000 vehicle with a $2,000 down payment, you will owe more than the car is worth for the first three to four years of a 72-month loan. If the car is totaled or stolen during this period, your insurance payment covers the actual cash value of the vehicle — not your loan balance. The gap (sometimes called GAP) must come out of your pocket unless you have separate GAP insurance. Aim for the shortest term you can genuinely afford, ideally 48 months or less. The higher monthly payment is the price of not being trapped in an underwater loan for years.

Putting 20% down on a new car is the standard recommendation for a straightforward reason: it approximately offsets the first-year depreciation, meaning you are not immediately underwater from the moment you drive off the lot. On a $35,000 car, a 20% down payment is $7,000 — and the car will likely be worth $26,000–$28,000 after 12 months. With $7,000 down, your loan balance stays below (or close to) the car's value throughout the life of a 48- or 60-month loan.

For used cars, the 10% recommendation reflects lower depreciation risk — a five-year-old car has already absorbed the steepest part of its depreciation curve. However, used cars often carry higher interest rates (7–12% vs. 3–6% for new cars with promotional financing), which means the loan term and down payment decisions are equally critical. One overlooked strategy: put at least enough down to cover taxes, title, and dealer fees out of pocket. These transaction costs add $1,500–$4,000 to the vehicle's price in most states. If you finance them, you are paying interest on fees — a particularly inefficient use of borrowed money. Arriving at the dealer with pre-approved financing and a specific down payment figure prevents the salesperson from structuring the deal around monthly payment rather than total cost.

Getting pre-approved by your bank or credit union before visiting the dealer is one of the most financially valuable steps you can take in a car purchase. Your pre-approval gives you a concrete rate to use as a baseline — if the dealer can beat it, great; if not, you already have your financing arranged. Without pre-approval, the dealer controls the financing conversation entirely, and many buyers end up accepting whatever rate the finance manager presents without knowing if it is competitive.

Dealers earn reserve income on auto loans — they mark up the interest rate above the buy rate (the rate the lender actually charges) and keep the difference as profit. This markup can range from 0.5% to 2.5%, and it is completely legal and undisclosed. A buyer who financed $25,000 at 7% instead of the 5% buy rate pays an extra $700–$800 in interest over a 60-month term. Credit unions consistently offer among the lowest auto loan rates for their members and do not mark up rates the way dealers do. Check your credit union first, then compare the dealer's offer against that baseline.

Manufacturer promotional financing (0% APR, 1.9% for 60 months, etc.) can be a genuine bargain when it applies to the vehicle you want — but always check whether accepting the promotional rate means forfeiting a cash rebate. A $3,000 rebate on a $35,000 vehicle financed at 6% generates roughly $2,400 in interest over 60 months. Taking the rebate and financing at 6% costs less than paying 0% without the rebate.