Car Loan Calculator

The True Cost of Your Car Before You Sign

The sticker price is just the beginning. By the time you factor in interest, taxes, and the term of the loan, the real cost of a vehicle can be thousands more than you expect. This calculator shows you the full picture so you can negotiate from a position of knowledge, not surprise.

How to Use This Calculator

Enter the vehicle price, your down payment, and any trade-in value, both of which reduce the amount you need to borrow. Select your loan term, enter the interest rate you've been quoted, and add your local sales tax rate if it applies. Hit Calculate Payment to see your monthly payment, total interest, and year-by-year amortization schedule.

How Car Loan Payments Are Calculated

Your loan amount is the vehicle price plus tax, minus your down payment and trade-in. The monthly payment is then calculated using the standard amortization formula:

Where M is the monthly payment, P is the loan amount, r is the monthly interest rate (annual rate ÷ 12), and n is the number of months. This is the same formula used for mortgages. The only difference is the numbers involved.

Real-World Example

Using the calculator's default values: a $35,000 vehicle, $5,000 down, 6.9% rate, 60-month term:

• Loan amount: $30,000
• Monthly payment: ~$593
• Total interest paid: ~$5,550
• Total cost of loan: ~$35,550

Now extend the same loan to 72 months to lower the payment:

• Monthly payment: ~$510 (saves $83/month)
• Total interest paid: ~$6,720
• Extra cost for the lower payment: $1,170 more in interest

You save $83/month but pay $1,170 more overall. Whether that trade-off makes sense depends entirely on your cash flow, but it's worth knowing the real cost before you decide.

The Real Cost of a Long Loan Term

Car dealers love long loan terms because they make expensive vehicles feel affordable. A $50,000 SUV at 7.5% over 84 months is "only" $762/month, but you'll pay over $14,000 in interest and still owe money on a 7-year-old vehicle. The longer the term, the more you pay and the longer you're at risk of being underwater.

As a general rule:

• 36–48 months: financially optimal, higher monthly payment, least total interest
• 60 months: a reasonable balance for most buyers
• 72–84 months: proceed with caution; significantly more interest and depreciation risk

Understanding Being "Underwater"

A new car loses roughly 15–25% of its value in the first year and up to 50% by year three. On a long loan term, your balance can easily exceed the car's market value for years, meaning if you need to sell or the car is totalled, you'd owe more than you'd receive. This is called being underwater or upside-down on the loan. A larger down payment and shorter term are the two best ways to avoid it.

Tips for Getting the Best Deal

• Get pre-approved before you shop. Walk into the dealership with a rate from your bank or credit union already in hand. Dealers often mark up financing by 1–2% above what they could offer. Your pre-approval gives you a ceiling to negotiate from.
• Negotiate the price, then the financing. Never discuss monthly payment with the dealer until the purchase price is agreed. Dealers use monthly payment to obscure the total cost of the vehicle.
• Put down at least 10–20%. This reduces your loan balance, lowers your payment, and protects you from going underwater early in the loan.
• Know your trade-in value independently. Check your vehicle's value on a third-party site before going to the dealer. Trade-in lowballing is one of the most common ways buyers lose money.
• Check your credit score first. Rates vary dramatically between credit tiers. Even improving your score by 30–50 points before applying can save you hundreds over the life of the loan.

Frequently Asked Questions