Estimate your monthly car payments and see the total cost of your vehicle loan.
Monthly Payment:$0.00
Total Loan Amount:$0.00
Total Interest Paid:$0.00
Total Cost (Loan + Down):$0.00
How to Use the Auto Loan Calculator
Buying a car is one of the most significant financial decisions you'll make. This tool helps you break down the costs associated with an auto loan so you can shop with confidence. To get started, enter the vehicle price, your down payment, and any trade-in value you might have. Then, input the interest rate and the length of the loan in months.
Key Factors That Influence Your Car Payment
Interest Rate (APR): This is the cost of borrowing the money. It is largely determined by your credit score. Lower scores usually result in higher interest rates.
Loan Term: Common terms range from 36 to 72 months. While a longer term lowers your monthly payment, it increases the total interest you pay over the life of the loan.
Down Payment: Putting more money down upfront reduces the principal amount of the loan, which lowers both your monthly payment and total interest costs.
Sales Tax: Don't forget that most states charge sales tax on vehicle purchases. Our calculator allows you to factor this into the total financed amount.
Realistic Auto Loan Example
Imagine you are purchasing a sedan for $30,000. You have a $5,000 down payment and a trade-in worth $2,000. If you secure a 5% interest rate for a 60-month term (5 years), your calculation would look like this:
Many car buyers make the mistake of focusing only on the monthly payment. Dealerships can often "lower" your monthly payment simply by extending the loan term to 72 or 84 months. While this makes the payment fit your monthly budget, it significantly increases the total amount of interest you pay. Always look at the Total Interest Paid and Total Cost before signing a contract.
function calculateAutoLoan() {
var price = parseFloat(document.getElementById('carPrice').value) || 0;
var down = parseFloat(document.getElementById('downPayment').value) || 0;
var trade = parseFloat(document.getElementById('tradeIn').value) || 0;
var rate = parseFloat(document.getElementById('interestRate').value) || 0;
var term = parseFloat(document.getElementById('loanTerm').value) || 0;
var tax = parseFloat(document.getElementById('salesTax').value) || 0;
if (price <= 0 || term <= 0) {
alert("Please enter a valid car price and loan term.");
return;
}
// Step 1: Calculate Net Price after down payment and trade-in
var netPrice = price – down – trade;
// Step 2: Apply Sales Tax to the net price (common calculation)
var taxAmount = netPrice * (tax / 100);
var loanAmount = netPrice + taxAmount;
if (loanAmount 0) {
var monthlyRate = (rate / 100) / 12;
// Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
monthlyPayment = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, term)) / (Math.pow(1 + monthlyRate, term) – 1);
totalInterest = (monthlyPayment * term) – loanAmount;
} else {
monthlyPayment = loanAmount / term;
totalInterest = 0;
}
var totalCost = loanAmount + totalInterest + down + trade;
// Display Results
document.getElementById('resMonthlyPayment').innerHTML = "$" + monthlyPayment.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('resLoanAmount').innerHTML = "$" + loanAmount.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('resTotalInterest').innerHTML = "$" + totalInterest.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('resTotalCost').innerHTML = "$" + totalCost.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('loanResultBox').style.display = "block";
}