Purchasing a vehicle is one of the most significant financial decisions you'll make. Our auto loan calculator helps you estimate your monthly payments and understand the total cost of ownership before you step onto the dealership lot. By adjusting the variables above, you can find a loan structure that fits your monthly budget.
Understanding the Components of Your Car Loan
Vehicle Price: The negotiated price of the car before taxes, fees, and down payments.
Down Payment & Trade-In: Cash or equity from your current vehicle that reduces the amount you need to borrow. A larger down payment significantly lowers your monthly obligation and total interest.
Interest Rate (APR): The annual cost of borrowing money, expressed as a percentage. This is heavily influenced by your credit score.
Loan Term: The duration of the loan. While longer terms (72-84 months) lower your monthly payment, they increase the total interest you pay over the life of the loan.
Example Calculation: Buying a $30,000 Sedan
If you purchase a vehicle for $30,000 with a $5,000 down payment at a 6% interest rate for 60 months (assuming 7% sales tax):
Total Loan Amount: $27,100 (Price + Tax – Down Payment)
Monthly Payment: Approximately $523.92
Total Interest Paid: $4,335.20
Total Cost: $36,435.20
Tips for a Better Auto Loan
To secure the best deal, check your credit score beforehand. Generally, a score above 700 qualifies you for the lowest rates. Additionally, consider getting pre-approved by your local bank or credit union; dealerships will often try to beat your pre-approved rate to earn your business.
function calculateAutoLoan() {
// Get Input Values
var price = parseFloat(document.getElementById('carPrice').value) || 0;
var down = parseFloat(document.getElementById('downPayment').value) || 0;
var trade = parseFloat(document.getElementById('tradeInValue').value) || 0;
var rateInput = parseFloat(document.getElementById('interestRate').value) || 0;
var term = parseInt(document.getElementById('loanTerm').value) || 0;
var taxPercent = parseFloat(document.getElementById('salesTax').value) || 0;
// Validation
if (price <= 0) {
alert("Please enter a valid vehicle price.");
return;
}
// Math Logic
var taxAmount = price * (taxPercent / 100);
var netPrice = price – down – trade;
var loanAmount = netPrice + taxAmount;
// Result display element
var resultDiv = document.getElementById('resultsArea');
resultDiv.style.display = "block";
if (loanAmount <= 0) {
document.getElementById('monthlyResult').innerText = "$0.00";
document.getElementById('totalLoanAmount').innerText = "$0.00";
document.getElementById('totalInterest').innerText = "$0.00";
document.getElementById('taxAmountResult').innerText = "$" + taxAmount.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('totalCost').innerText = "$" + (price + taxAmount).toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
return;
}
var monthlyRate = (rateInput / 100) / 12;
var monthlyPayment = 0;
if (monthlyRate === 0) {
monthlyPayment = loanAmount / term;
} else {
// Formula: P * (r(1+r)^n) / ((1+r)^n – 1)
var x = Math.pow(1 + monthlyRate, term);
monthlyPayment = (loanAmount * monthlyRate * x) / (x – 1);
}
var totalPaid = (monthlyPayment * term);
var totalInterest = totalPaid – loanAmount;
var totalProjectedCost = price + taxAmount + totalInterest;
// Formatting outputs
document.getElementById('monthlyResult').innerText = "$" + monthlyPayment.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('totalLoanAmount').innerText = "$" + loanAmount.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('totalInterest').innerText = "$" + totalInterest.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('taxAmountResult').innerText = "$" + taxAmount.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('totalCost').innerText = "$" + totalProjectedCost.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
// Smooth scroll to results
resultDiv.scrollIntoView({ behavior: 'smooth', block: 'nearest' });
}