What is an auto loan?
An auto loan is a secured installment loan used to finance the purchase of a vehicle. You borrow a set amount from a lender — a bank, credit union, or dealership — and repay it in fixed monthly payments over a term typically ranging from 24 to 84 months. The vehicle itself serves as collateral, meaning the lender can repossess it if you stop making payments. Auto loans are one of the most common forms of consumer debt in the United States, with the average car payment exceeding $700 per month for new vehicles in 2024.
How can an auto loan calculator help you?
Dealerships are experts at steering buyers toward focusing on monthly payments rather than total cost. An auto loan calculator helps you see the full picture — how much you will pay in total, how much goes to interest, and how different loan terms, down payments, or trade-in values change the equation. Use it before you visit a dealership so you walk in knowing exactly what a fair deal looks like, and use it to compare financing from your bank or credit union against whatever the dealer offers.
How is a car payment calculated?
Monthly auto loan payments are calculated using the same standard loan amortization formula as mortgages:
The Formula
- M= Monthly payment
- P= Principal (car price – down payment – trade-in + taxes & fees)
- r= Monthly interest rate (annual APR ÷ 12)
- n= Total number of payments (loan term in months)
How to use Finzony's auto loan calculator
Get your complete car payment breakdown in seconds:
- Enter the vehicle price: The sticker price or agreed purchase price of the car. Do not include taxes or fees — enter those separately below.
- Set your down payment: The amount of cash you plan to pay upfront. More down = smaller loan = less interest. Aim for at least 10–20%.
- Enter your trade-in value: What your current vehicle is worth. This reduces the purchase price (and in most states, the taxable amount) of the new car.
- Set the interest rate (APR): Use the rate you have been pre-approved for, or the dealer's offered rate. Getting pre-approved before visiting a dealer gives you a strong negotiating position.
- Choose your loan term: 60 months is most common. Shorter terms save interest; longer terms lower the monthly payment but cost more overall.
- Add sales tax and fees: Enter your state's sales tax rate and any estimated dealer fees to see your true out-of-pocket monthly cost.
The 20/4/10 Rule
Put 20% down, finance for no more than 4 years, and keep total car costs under 10% of gross monthly income.
GAP Insurance
If your loan balance is more than the car's value, GAP insurance covers the difference if it's totaled or stolen.
Pre-Approval Power
Getting a loan pre-approved from a credit union before visiting a dealer can save 1–2% in interest rate.
20%
Recommended down payment
60mo
Most common loan term
740+
Credit score for best APR
10%
Max car cost of income
Why use Finzony's auto loan calculator?
- See Your True Monthly Cost: Goes beyond principal and interest — includes sales tax, dealer fees, and trade-in credit so you know your real out-of-pocket payment before you sign anything.
- Loan Term Comparison: Instantly see how a 48, 60, or 72-month term affects both your monthly payment and total interest paid. Longer terms cost far more in the long run.
- Trade-In & Tax Savings: Enter your trade-in value and see the tax savings it generates. In most states, trade-ins reduce the taxable price of the new vehicle — a benefit many buyers miss.
- Full Amortization Schedule: See exactly how your balance decreases month by month. Identify the break-even point where your car is worth more than you owe — critical for avoiding being underwater.