Understanding how a car lease payment is calculated can save you thousands of dollars at the dealership. Unlike a traditional auto loan where you pay for the entire vehicle, a lease only charges you for the depreciation that occurs during the time you drive the car.
The Key Components of a Lease
Gross Capitalized Cost: This is the negotiated price of the vehicle plus any additional fees or taxes rolled into the lease.
Residual Value: This is the estimated value of the car at the end of the lease term. It is set by the leasing company and is usually a percentage of the MSRP.
Money Factor: This is the interest rate on the lease. To convert a money factor to an APR, multiply it by 2400. For example, a money factor of 0.00125 is equivalent to a 3% APR.
Depreciation Fee: The difference between the capitalized cost and the residual value, divided by the number of months in the lease.
The Math Behind the Payment
To calculate the monthly payment manually, you add the monthly depreciation fee to the monthly rent charge (interest). The formula for the rent charge is unique: it is the (Capitalized Cost + Residual Value) multiplied by the Money Factor.
To lower your monthly lease payment, focus on three things: negotiating a lower sale price (Capitalized Cost), choosing a vehicle with a high residual value, and checking for "subvented" or promotional money factors offered by the manufacturer.
function calculateLease() {
// Get values from inputs
var msrp = parseFloat(document.getElementById("msrp").value);
var salePrice = parseFloat(document.getElementById("salePrice").value);
var downPayment = parseFloat(document.getElementById("downPayment").value) || 0;
var tradeIn = parseFloat(document.getElementById("tradeIn").value) || 0;
var term = parseFloat(document.getElementById("term").value);
var residualPercent = parseFloat(document.getElementById("residualPercent").value);
var moneyFactor = parseFloat(document.getElementById("moneyFactor").value);
var salesTax = parseFloat(document.getElementById("salesTax").value);
// Basic Validation
if (isNaN(msrp) || isNaN(salePrice) || isNaN(residualPercent) || isNaN(moneyFactor)) {
alert("Please enter valid numbers for MSRP, Sale Price, Residual, and Money Factor.");
return;
}
// Calculation Logic
// 1. Adjusted Capitalized Cost
var adjCapCost = salePrice – (downPayment + tradeIn);
// 2. Residual Value Calculation
var residualValue = msrp * (residualPercent / 100);
// 3. Monthly Depreciation
var monthlyDepreciation = (adjCapCost – residualValue) / term;
// If depreciation is negative (rare), set to 0
if (monthlyDepreciation < 0) monthlyDepreciation = 0;
// 4. Monthly Rent Charge
var monthlyRentCharge = (adjCapCost + residualValue) * moneyFactor;
// 5. Base Monthly Payment
var basePayment = monthlyDepreciation + monthlyRentCharge;
// 6. Tax Calculation
var taxAmount = basePayment * (salesTax / 100);
var totalMonthly = basePayment + taxAmount;
// 7. Total Lease Cost (Monthly payments + down payment + trade-in)
var totalCost = (totalMonthly * term) + downPayment + tradeIn;
// Display Results
document.getElementById("preTaxResult").innerHTML = "$" + basePayment.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("totalMonthlyResult").innerHTML = "$" + totalMonthly.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("totalCostResult").innerHTML = "$" + totalCost.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
// Show results area
document.getElementById("results-area").style.display = "block";
// Scroll to results
document.getElementById("results-area").scrollIntoView({ behavior: 'smooth', block: 'nearest' });
}