Estimate your monthly auto financing costs instantly.
Total Loan Amount:$0.00
Total Interest Paid:$0.00
Total Cost (Principal + Interest):$0.00
Monthly Payment:$0.00
How to Use the Car Loan Calculator
Buying a car is one of the most significant financial decisions you will make. Our Car Loan Monthly Payment Calculator is designed to help you understand the long-term impact of interest rates and loan terms on your wallet. By adjusting the variables, you can find a monthly payment that fits comfortably within your budget.
Understanding the Inputs
Vehicle Price: The sticker price or negotiated price of the car before taxes and fees.
Down Payment: The cash you pay upfront. A higher down payment reduces your loan balance and total interest.
Trade-in Value: The amount a dealer offers for your current vehicle, which acts as a credit against the purchase price.
Interest Rate (APR): The annual percentage rate charged by the lender. This is determined by your credit score and current market trends.
Loan Term: The duration of the loan in months. Common terms are 36, 48, 60, or 72 months.
The Math Behind Your Auto Loan
Car loans typically use an amortization formula. This means that in the early stages of your loan, a larger portion of your monthly payment goes toward interest, while later payments apply more heavily to the principal balance.
The formula used in this calculator is: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
Where:
M = Monthly payment
P = Principal loan amount (Price – Down Payment – Trade-in + Sales Tax)
i = Monthly interest rate (Annual rate divided by 12)
n = Number of months in the loan term
Real-World Example
Let's say you buy a SUV for $35,000. You provide a $5,000 down payment and have no trade-in. Your local bank offers you a 5% interest rate for 60 months (5 years).
Your total loan amount would be $30,000. Using the formula, your monthly payment would be approximately $566.14. Over the life of the loan, you would pay a total of $3,968.22 in interest.
Tips for Lowering Your Monthly Payment
If the results from the calculator are higher than you expected, consider these three strategies:
Improve Your Credit Score: Even a 1% drop in your interest rate can save you thousands of dollars over the life of the loan.
Extend the Term: Moving from a 48-month loan to a 60-month loan will lower your monthly payment, but be aware that you will pay more in total interest.
Increase Down Payment: Aim for at least 20% down. This helps prevent "negative equity," which is when you owe more on the car than it is worth.
function calculateCarLoan() {
var price = parseFloat(document.getElementById("vehiclePrice").value) || 0;
var down = parseFloat(document.getElementById("downPayment").value) || 0;
var trade = parseFloat(document.getElementById("tradeValue").value) || 0;
var rate = parseFloat(document.getElementById("interestRate").value) || 0;
var months = parseInt(document.getElementById("loanTerm").value) || 0;
var taxPercent = parseFloat(document.getElementById("salesTax").value) || 0;
if (price <= 0 || months <= 0) {
alert("Please enter a valid vehicle price and loan term.");
return;
}
// Calculate Sales Tax on the price
var taxAmount = price * (taxPercent / 100);
// Calculate Principal
var principal = (price + taxAmount) – down – trade;
if (principal 0) {
var monthlyRate = (rate / 100) / 12;
monthlyPayment = (principal * monthlyRate * Math.pow(1 + monthlyRate, months)) / (Math.pow(1 + monthlyRate, months) – 1);
totalInterest = (monthlyPayment * months) – principal;
} else {
monthlyPayment = principal / months;
totalInterest = 0;
}
var totalCost = principal + totalInterest;
// Display Results
document.getElementById("resultBox").style.display = "block";
document.getElementById("resLoanAmount").innerText = "$" + principal.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("resTotalInterest").innerText = "$" + totalInterest.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("resTotalCost").innerText = "$" + totalCost.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("resMonthlyPayment").innerText = "$" + monthlyPayment.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
}