function calculateLease() {
var msrp = parseFloat(document.getElementById('msrp').value);
var downPayment = parseFloat(document.getElementById('downPayment').value) || 0;
var tradeIn = parseFloat(document.getElementById('tradeIn').value) || 0;
var term = parseInt(document.getElementById('leaseTerm').value);
var residualPercent = parseFloat(document.getElementById('residualPercent').value);
var apr = parseFloat(document.getElementById('apr').value);
var taxRate = parseFloat(document.getElementById('salesTax').value);
if (isNaN(msrp) || msrp <= 0) {
alert('Please enter a valid MSRP.');
return;
}
// Calculate Gross Capitalized Cost (assuming no extra fees for simplicity)
var capCost = msrp – downPayment – tradeIn;
// Calculate Residual Value
var residualValue = msrp * (residualPercent / 100);
// Calculate Monthly Depreciation
var depreciationFee = (capCost – residualValue) / term;
// Calculate Rent Charge (Interest)
// Rent Charge = (Net Cap Cost + Residual) × Money Factor
// Money Factor = APR / 2400
var moneyFactor = apr / 2400;
var rentCharge = (capCost + residualValue) * moneyFactor;
// Base Monthly Payment
var basePayment = depreciationFee + rentCharge;
// Monthly Tax
var monthlyTax = basePayment * (taxRate / 100);
// Total Monthly Payment
var totalMonthly = basePayment + monthlyTax;
// Update UI
document.getElementById('monthlyPaymentDisplay').innerText = '$' + totalMonthly.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('depreciationPart').innerText = '$' + depreciationFee.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('rentPart').innerText = '$' + rentCharge.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('taxPart').innerText = '$' + monthlyTax.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('totalCapCost').innerText = '$' + capCost.toLocaleString();
document.getElementById('residualAmt').innerText = '$' + residualValue.toLocaleString();
document.getElementById('resultArea').style.display = 'block';
}
How to Use the Car Lease Calculator
Leasing a vehicle can be more complex than a standard auto loan. Our car lease calculator helps you break down the monthly costs so you can negotiate a better deal at the dealership. To get an accurate estimate, you will need several key pieces of information:
Key Leasing Terms Explained
MSRP: The Manufacturer's Suggested Retail Price. This is the "sticker price" of the car.
Capitalized Cost (Cap Cost): The price you negotiate for the vehicle. In this calculator, we subtract your down payment and trade-in from the MSRP to find your "Net Cap Cost."
Residual Value: What the car is worth at the end of the lease. It is usually expressed as a percentage of the MSRP. A higher residual value means lower monthly payments because you are paying for less depreciation.
Money Factor: This is essentially the interest rate for a lease. To convert APR to Money Factor, divide by 2400. Our calculator handles this conversion automatically.
Lease Term: The duration of your lease agreement, typically 24, 36, or 48 months.
Lease Calculation Example
Imagine you are looking at a luxury sedan with an MSRP of $45,000. You negotiate a deal where you put down $5,000 and have no trade-in. The bank sets a 36-month residual at 58% and an APR of 4.0%. Your local sales tax is 8%.
To lower your monthly payment, focus on three things: negotiating the Gross Capitalized Cost (the sales price) just as if you were buying the car, choosing a vehicle with a high Residual Value, and checking for Lease Specials which often offer lower Money Factors than standard bank rates.