Auto Loan Calculator Guide: Monthly Payments, APR vs. interest rate guide and Total Cost Explained
Auto loans are one of the most expensive purchases most Americans make, yet most buyers focus only on the monthly payment calculator. Learn the true cost of financing, how dealer markup works, and the strategies that can save thousands on your next vehicle.
The Auto Loan Payment Formula
Auto loans use the same standard amortization schedule formula as mortgages and personal loan comparison s. Every auto payment covers two components: interest on the current outstanding balance and principal reduction. The proportion shifts over the loan term guide — early payments are majority interest, later payments are majority principal. For a
How Loan Term Affects Total Cost
Longer loan terms lower monthly payments but dramatically increase total interest paid and create the risk of being underwater (owing more than the car is worth) for extended periods. $28,000 loan at 7% APR across different terms: 36 months: $864/month, $3,104 total interest, 36-month underwater risk 48 months: $670/month, $4,160 total interest 60
Dealer Financing Markup: The Hidden Rate Premium
When you finance through a dealership, the process involves three parties: you, the dealer, and the lending institution (bank, credit union, or captive lender like Ford Credit). The dealer functions as a financing broker — they receive a wholesale rate from the lender and mark it up before presenting it to you as your 'approval rate.' The markup —
New vs. Used Vehicle Financing: Rate and Depreciation Differences
New and used vehicles are financed differently, and the implications for total cost are significant. Interest rates: New vehicle loans from most lenders are priced 0.5%–2% lower than used vehicle loans for the same borrower. The reason: new vehicles have standardized values (MSRP is public) and lower repossession risk than used vehicles with uncert
Frequently Asked Questions
How do I calculate my auto loan monthly payment?
Use the formula M = P × [r(1+r)^n] / [(1+r)^n − 1], where P is the loan amount, r is the monthly rate (APR ÷ 12), and n is the loan term in months. For a $25,000 loan at 6% APR for 60 months: r = 0.005, n = 60, payment = $483.32/month. Total paid: $28,999. Total interest: $3,999.
What is a good interest rate for a car loan?
In 2025, competitive auto loan rates for borrowers with good credit (700+ FICO): 5%–8% for new vehicles, 6%–10% for used vehicles from a credit union or direct lender. Dealer-arranged financing typically runs 1%–2% higher than credit union rates for the same borrower. Manufacture
Should I put money down on a car loan?
Yes — a down payment of 10%–20% is recommended. It reduces total loan cost (less interest paid), shortens the underwater period (when you owe more than the car is worth), and lowers the monthly payment. The most important function is avoiding being underwater — new vehicles depre
Is a 72-month car loan a bad idea?
Generally yes for most buyers. A 72-month auto loan extends your underwater period to 4+ years, adds $1,000–$2,000 in total interest vs. 60 months, and ties up financing capacity for 6 years. If the only way to afford a vehicle is a 72-month loan, consider whether the vehicle is
Can I get a car loan with a 600 credit score?
Yes — many lenders approve auto loans at 600 FICO, but at significantly higher rates. Subprime auto rates at 600 FICO typically range from 12%–20% APR. On a $20,000 loan at 15% for 60 months: payment = $476/month, total interest = $8,560 — more than 40% of the vehicle price in in
What is dealer financing markup?
Dealer financing markup is the difference between the wholesale buy rate a lender quotes the dealer and the rate the dealer presents to you. Dealers earn a portion of this spread as compensation for originating the loan. Federal regulations cap the markup at 2%–2.5% for many prog