function calculateLeaseVsBuy() {
// Buy Logic
var buyPrice = parseFloat(document.getElementById('buyPrice').value) || 0;
var buyDown = parseFloat(document.getElementById('buyDown').value) || 0;
var buyAPR = parseFloat(document.getElementById('buyAPR').value) || 0;
var buyTerm = parseFloat(document.getElementById('buyMonths').value) || 1;
var buyResale = parseFloat(document.getElementById('buyResale').value) || 0;
var principal = buyPrice – buyDown;
var monthlyRate = (buyAPR / 100) / 12;
var buyMonthlyPayment = 0;
if (monthlyRate === 0) {
buyMonthlyPayment = principal / buyTerm;
} else {
buyMonthlyPayment = (principal * monthlyRate) / (1 – Math.pow(1 + monthlyRate, -buyTerm));
}
var totalInterest = (buyMonthlyPayment * buyTerm) – principal;
var totalBuyCost = (buyMonthlyPayment * buyTerm) + buyDown – buyResale;
var buyEffectiveMonthly = totalBuyCost / buyTerm;
// Lease Logic
var leaseMonthly = parseFloat(document.getElementById('leaseMonthly').value) || 0;
var leaseDown = parseFloat(document.getElementById('leaseDown').value) || 0;
var leaseTerm = parseFloat(document.getElementById('leaseMonths').value) || 1;
var leaseFee = parseFloat(document.getElementById('leaseFee').value) || 0;
var totalLeaseCost = (leaseMonthly * leaseTerm) + leaseDown + leaseFee;
var leaseEffectiveMonthly = totalLeaseCost / leaseTerm;
// Display results
document.getElementById('comparisonResult').style.display = 'block';
document.getElementById('buyTotalRes').innerHTML = '$' + totalBuyCost.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('buyMonthlyRes').innerHTML = 'Loan Pmt: $' + buyMonthlyPayment.toLocaleString(undefined, {maximumFractionDigits: 0}) + '/mo';
document.getElementById('leaseTotalRes').innerHTML = '$' + totalLeaseCost.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('leaseMonthlyRes').innerHTML = 'Eff. Cost: $' + leaseEffectiveMonthly.toLocaleString(undefined, {maximumFractionDigits: 0}) + '/mo';
var verdict = document.getElementById('verdictTitle');
var summary = document.getElementById('comparisonSummary');
if (buyEffectiveMonthly < leaseEffectiveMonthly) {
verdict.innerHTML = "🏆 Buying is more cost-effective";
verdict.style.color = "#0550ae";
summary.innerHTML = "By financing and selling later, you save approximately $" + (leaseEffectiveMonthly – buyEffectiveMonthly).toLocaleString(undefined, {maximumFractionDigits: 0}) + " per month compared to leasing.";
} else {
verdict.innerHTML = "🏆 Leasing is more cost-effective";
verdict.style.color = "#1a7f37";
summary.innerHTML = "Leasing saves you approximately $" + (buyEffectiveMonthly – leaseEffectiveMonthly).toLocaleString(undefined, {maximumFractionDigits: 0}) + " per month over the term of the agreement.";
}
}
Leasing vs. Buying a Car: Which is Right for You?
Choosing between leasing and buying a car is one of the most significant financial decisions for many households. While buying a car typically leads to long-term ownership and equity, leasing offers lower monthly payments and the ability to drive a new vehicle every few years.
The True Cost of Ownership
To accurately compare the two, you must look beyond the monthly payment. Our calculator evaluates the Net Cost, which accounts for:
Depreciation: The loss in value over time. For buyers, the resale value at the end of the loan is their "recovery" of costs.
Interest & Fees: Financing involves APR, while leasing includes money factors and acquisition/disposition fees.
Equity: When you buy, you own an asset. When you lease, you are simply paying for the vehicle's use during its most expensive years of life.
Example Scenario
Imagine you are looking at a $35,000 SUV.
Buying: With $5,000 down and a 5.5% interest rate over 60 months, your payment is roughly $573. After 5 years, if the car is worth $18,000, your total "spent" (net cost) is about $21,380.
Leasing: You pay $2,500 at signing and $450/month for 36 months. After 3 years, you return the car and have spent $18,700 total.
In this case, the lease seems cheaper, but remember the buyer owns an $18,000 asset at the end, whereas the lessee has nothing.
When Should You Lease?
Leasing is generally best if you want a lower monthly payment, prefer to have the latest safety technology every 3 years, and drive a predictable number of miles (usually under 12,000 per year). It is also advantageous for business owners who can often deduct lease payments as a business expense.
When Should You Buy?
Buying is the superior financial move if you plan to keep the vehicle for more than 5 years. Once the loan is paid off, you can drive for years with no monthly payment, significantly reducing your long-term transportation costs. Buying also eliminates "excess wear and tear" fees and mileage restrictions.