Navy Federal Credit Union Mortgage Loan Calculator
by
Car Lease vs. Buy Comparison Calculator
Leasing Details
Buying Details
Leasing Cost
Monthly Payment
Total Cost (Term)
Buying Cost
Monthly Payment
Net Cost (Term – Equity)
function calculateComparison() {
var price = parseFloat(document.getElementById('vehiclePrice').value) || 0;
// Lease Logic
var leaseTerm = parseFloat(document.getElementById('leaseTerm').value) || 0;
var leaseDown = parseFloat(document.getElementById('leaseDown').value) || 0;
var mf = parseFloat(document.getElementById('moneyFactor').value) || 0;
var resPct = parseFloat(document.getElementById('residualPercent').value) || 0;
var residualVal = price * (resPct / 100);
var capCost = price – leaseDown;
var depreciation = (capCost – residualVal) / leaseTerm;
var financeFee = (capCost + residualVal) * mf;
var monthlyLease = depreciation + financeFee;
var totalLeaseCost = (monthlyLease * leaseTerm) + leaseDown;
// Buy Logic
var loanTerm = parseFloat(document.getElementById('loanTerm').value) || 0;
var buyDown = parseFloat(document.getElementById('buyDown').value) || 0;
var apr = parseFloat(document.getElementById('interestRate').value) || 0;
var resaleVal = parseFloat(document.getElementById('futureValue').value) || 0;
var loanPrincipal = price – buyDown;
var monthlyRate = (apr / 100) / 12;
var monthlyBuy = 0;
if(monthlyRate > 0) {
monthlyBuy = loanPrincipal * (monthlyRate * Math.pow(1 + monthlyRate, loanTerm)) / (Math.pow(1 + monthlyRate, loanTerm) – 1);
} else {
monthlyBuy = loanPrincipal / loanTerm;
}
// Total cost over the SAME term as the lease for fair comparison
var totalLoanPaidDuringLeasePeriod = (monthlyBuy * leaseTerm) + buyDown;
// Balance remaining on loan after lease period
var balanceRemaining = loanPrincipal;
for(var i=0; i < leaseTerm; i++) {
var interest = balanceRemaining * monthlyRate;
var principal = monthlyBuy – interest;
balanceRemaining -= principal;
}
// Net cost of buying = (Payments made + Down) – (Equity if sold)
// Equity = Resale Value – Loan Balance
var equity = resaleVal – Math.max(0, balanceRemaining);
var netBuyCost = totalLoanPaidDuringLeasePeriod – equity;
// Display Results
document.getElementById('results').style.display = 'block';
document.getElementById('leaseMonthly').innerText = '$' + monthlyLease.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('leaseTotal').innerText = '$' + totalLeaseCost.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('buyMonthly').innerText = '$' + monthlyBuy.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('buyTotal').innerText = '$' + netBuyCost.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
var recDiv = document.getElementById('recommendation');
if (netBuyCost < totalLeaseCost) {
var savings = totalLeaseCost – netBuyCost;
recDiv.style.backgroundColor = '#e6f4ea';
recDiv.style.color = '#1e8e3e';
recDiv.innerHTML = 'Buying is more cost-effective! You save approx. $' + savings.toLocaleString(undefined, {maximumFractionDigits: 0}) + ' over ' + leaseTerm + ' months.';
} else {
var savings = netBuyCost – totalLeaseCost;
recDiv.style.backgroundColor = '#fdf2f2';
recDiv.style.color = '#d93025';
recDiv.innerHTML = 'Leasing is more cost-effective! You save approx. $' + savings.toLocaleString(undefined, {maximumFractionDigits: 0}) + ' over ' + leaseTerm + ' months.';
}
}
Should You Lease or Buy Your Next Car?
Deciding between leasing and buying a car is one of the most significant financial decisions for any household. While leasing offers lower monthly payments and the ability to drive a new model every few years, buying builds equity and long-term value. Our Lease vs. Buy Calculator helps you compare the true total cost of ownership by looking beyond just the monthly payment.
Understanding the Math: Lease vs. Buy
When you lease, you are essentially paying for the depreciation of the vehicle over a fixed term (usually 36 months), plus a finance charge called the Money Factor. When the lease ends, you return the car and have no equity.
When you buy, your monthly payments are usually higher because you are paying off the entire principal of the loan. However, at the end of the term, you own an asset. To compare them fairly, our calculator looks at the Net Cost: the total money spent minus the value of the car (equity) at the end of the term.
Key Factors to Consider
Mileage: Leases come with strict limits (typically 10,000 to 15,000 miles per year). If you drive long distances, buying is almost always better to avoid hefty overage fees.
Maintenance: Leased cars are usually under the manufacturer's warranty for the duration of the term, minimizing unexpected repair costs.
Customization: Buying allows you to modify the car as you wish. Leases require the car to be returned in "as-new" condition, meaning no permanent modifications.
Money Factor: This is the lease equivalent of an APR. To find the approximate interest rate, multiply the money factor by 2,400 (e.g., 0.0025 x 2400 = 6% APR).
A Realistic Example
Imagine a SUV priced at $35,000:
Lease: With a $2,000 down payment and a 60% residual value, your monthly payment might be around $450. Total out-of-pocket over 3 years: ~$18,200.
Buy: With $5,000 down and 5% interest over 5 years, your payment is ~$566. After 3 years, you've paid $25,376 total. If the car is still worth $21,000 and you owe $13,000, you have $8,000 in equity. Your net cost is $25,376 – $8,000 = $17,376.
In this scenario, buying saves you about $824 over three years compared to leasing, despite the higher monthly obligation.