Car Loan Calculator with Extra Payments & Amortization Schedule
A car loan calculator is a free online tool that computes your monthly auto loan payment from the vehicle price, down payment, trade-in, sales tax, fees, term and APR — then models extra monthly, yearly and one-time payments and builds a full amortization schedule, entirely in your browser with no sign-up and no dealer lead forms.
100% private — your numbers never leave this page
Your monthly car payment
$0/ month
Amount financed
—
Total interest
—
Total of payments
—
Payoff date
—
Sales tax
—
Out-the-door price
—
With your extra payments
Interest saved
—
Time saved
—
New payoff
—
Loan balance over time
Amortization schedule
Period
Principal
Interest
Extra
Balance
How to use this car loan calculator
1
Enter the deal
Type the vehicle price, your down payment and any trade-in value, then add your sales tax rate and title or dealer fees so the amount financed is realistic.
2
Pick a term & APR
Tap a term preset (36–84 months) and enter your interest rate. The monthly payment and total interest update instantly so you can compare loan lengths.
3
Add extra payments
Try an extra monthly amount, one payment a year or a lump sum, then read your payoff date, interest saved and the amortization table — and download it as CSV.
How the car loan payment formula works
Auto loans are fixed-rate and fully amortizing, so they use the standard loan payment formula. Your monthly payment is:
M = P × r(1 + r)n / ((1 + r)n − 1)
where P is the amount financed, r is the monthly interest rate (your APR ÷ 12), and n is the loan term in months. The amount financed is the vehicle price plus sales tax and fees, minus your cash down payment and trade-in equity. For a $30,500 amount financed at 7.5% APR over 60 months that works out to about $611 per month.
Each month interest is charged on the remaining balance and the rest of your payment reduces the principal. Early payments are mostly interest, later ones almost all principal — the amortization schedule above shows the exact split for every single payment.
How extra payments pay off your car loan faster
On a fixed-rate auto loan every extra dollar you pay goes straight to principal. A smaller balance means less interest accrues each month, so more of every following payment also attacks principal — the savings compound for the rest of the loan and you own the car outright sooner.
Extra monthly payment. Adding even $50–$100 a month to a typical 5-year loan shaves months off the term and saves hundreds in interest, and it lowers the risk of being "upside down" (owing more than the car is worth).
One extra payment a year. Putting a bonus or tax refund toward the loan once a year is an easy way to shorten the term without straining your monthly budget.
One-time lump sum. A lump sum applied early in the loan saves far more than the same amount applied late, because it stops interest on that principal for the whole remaining term.
Extra payments do not lower your required monthly payment — they shorten the loan. Confirm your lender applies extra amounts to principal (not to the next due date) and check for any prepayment penalty; most US auto loans have none.
Trade-in, sales tax and fees explained
The sticker price is rarely what you finance. This calculator builds the real amount financed from every part of the deal:
Trade-in value — the dealer's offer for your current car reduces what you borrow. If you still owe money on it, that balance ("still owed on trade-in") is rolled into the new loan as negative equity.
Sales tax — in most US states tax is charged on the price after the trade-in (the trade-in tax credit), which can save hundreds of dollars. A few states tax the full price — raise the tax rate or set trade-in to zero to model that.
Title & fees — registration, title and dealer documentation fees are usually financed into the loan. Watch dealer add-ons; they increase both the amount financed and the interest you pay.
APR vs interest rate — APR includes most loan fees, so use the APR your lender quotes for the most accurate payment.
Because all of the math runs locally in your browser, you can test scenarios freely — a bigger down payment, a 48 vs 72-month term, a different APR from your bank or credit union — without creating an account or getting sales calls. Nothing you type is uploaded, stored or shared.
Car loan calculator FAQ
How is a car loan monthly payment calculated?
It uses the amortization formula M = P × r(1+r)ⁿ / ((1+r)ⁿ − 1), where P is the amount financed, r the monthly rate (APR ÷ 12) and n the term in months. The amount financed is the vehicle price plus sales tax and fees, minus your down payment and trade-in equity.
Do extra payments pay off a car loan faster?
Yes. On a fixed-rate auto loan extra money goes straight to principal, so the balance drops faster, less interest accrues and the loan ends before the term is up. The green panel above shows exactly how much time and interest you save.
Does a trade-in reduce the sales tax on a car?
In most US states yes — sales tax is charged on the price minus your trade-in value, which can save hundreds of dollars. A few states tax the full price; raise the tax rate or set trade-in to zero to model that.
Is 60 or 72 months a better car loan term?
A shorter term means a higher monthly payment but much less total interest and less risk of going upside down. A 72 or 84-month loan lowers the payment but costs far more interest. Use the term presets to compare instantly.
Is this car loan calculator free and private?
Yes — completely free, no sign-up, no lead forms, no dealer calls. Every calculation runs locally in your browser with JavaScript; the numbers you enter are never sent to a server.
What is an auto loan amortization schedule?
A payment-by-payment table showing how each payment splits between interest and principal and what balance remains. View it yearly or monthly above, and download the full schedule as a CSV for Excel or Google Sheets.
Disclaimer: this calculator provides estimates for educational purposes only and is not financial advice or a loan offer. Actual payments depend on your lender's terms, exact APR, closing date, taxes and fees. Always confirm figures with your lender or credit union before making decisions.