Estimate your monthly auto loan payments, total interest, and total cost of ownership.
Monthly Payment:
Total Loan Amount:
Total Interest Paid:
Total Cost (Price + Tax + Interest):
How to Calculate Your Car Loan Payment
Using a car loan calculator helps you understand the long-term financial commitment of purchasing a new or used vehicle. The calculation involves more than just dividing the price by the number of months; it includes interest compounding and initial costs like sales tax and down payments.
The formula used for calculating a fixed-rate auto loan is:
M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
M: Monthly Payment
P: Principal Loan Amount (Vehicle price + tax – down payment)
i: Monthly Interest Rate (Annual rate divided by 12)
n: Number of months in the loan term
Typical Car Loan Examples
Vehicle Price
Down Payment
Term
Rate
Est. Monthly Payment
$25,000
$3,000
60 Mo
5%
$415.17
$45,000
$5,000
72 Mo
6%
$662.80
$60,000
$10,000
48 Mo
4%
$1,128.12
Tips for Lowering Your Monthly Payment
If the results from the calculator are higher than your budget allows, consider these strategies:
Increase Down Payment: Every thousand dollars you pay upfront significantly reduces the principal and interest paid over time.
Improve Your Credit Score: A higher credit score often unlocks lower interest rates, which can save thousands over the life of the loan.
Extend the Term: While a longer term (e.g., 72 or 84 months) lowers the monthly payment, it increases the total interest you will pay.
Negotiate the Price: Lowering the purchase price of the vehicle is the most direct way to reduce every metric in this calculator.
function calculateCarLoan() {
var carPrice = parseFloat(document.getElementById("carPrice").value);
var downPayment = parseFloat(document.getElementById("downPayment").value) || 0;
var tradeIn = parseFloat(document.getElementById("tradeIn").value) || 0;
var interestRate = parseFloat(document.getElementById("interestRate").value);
var loanTerm = parseFloat(document.getElementById("loanTerm").value);
var salesTax = parseFloat(document.getElementById("salesTax").value) || 0;
if (isNaN(carPrice) || isNaN(interestRate) || isNaN(loanTerm) || carPrice <= 0) {
alert("Please enter valid positive numbers for price, interest, and term.");
return;
}
// Calculation Logic
var taxAmount = carPrice * (salesTax / 100);
var principal = carPrice + taxAmount – downPayment – tradeIn;
if (principal <= 0) {
document.getElementById("resMonthly").innerText = "$0.00";
document.getElementById("resTotalLoan").innerText = "$0.00";
document.getElementById("resInterest").innerText = "$0.00";
document.getElementById("resTotalCost").innerText = "$0.00";
document.getElementById("loanResult").style.display = "block";
return;
}
var monthlyRate = (interestRate / 100) / 12;
var monthlyPayment = 0;
if (monthlyRate === 0) {
monthlyPayment = principal / loanTerm;
} else {
monthlyPayment = principal * (monthlyRate * Math.pow(1 + monthlyRate, loanTerm)) / (Math.pow(1 + monthlyRate, loanTerm) – 1);
}
var totalPayment = monthlyPayment * loanTerm;
var totalInterest = totalPayment – principal;
var totalCost = totalPayment + downPayment + tradeIn;
// Display Results
document.getElementById("resMonthly").innerText = "$" + monthlyPayment.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("resTotalLoan").innerText = "$" + principal.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("resInterest").innerText = "$" + totalInterest.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("resTotalCost").innerText = "$" + totalCost.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("loanResult").style.display = "block";
}