*This estimate does not include acquisition fees, documentation fees, or registration costs which vary by dealer and state.
function calculateLease() {
var price = parseFloat(document.getElementById('carPrice').value);
var resPercent = parseFloat(document.getElementById('residualPercent').value) / 100;
var term = parseFloat(document.getElementById('leaseTerm').value);
var mf = parseFloat(document.getElementById('moneyFactor').value);
var down = parseFloat(document.getElementById('downPayment').value);
var taxRate = parseFloat(document.getElementById('salesTax').value) / 100;
if (isNaN(price) || isNaN(resPercent) || isNaN(term) || isNaN(mf) || isNaN(down) || isNaN(taxRate) || term <= 0) {
alert("Please enter valid positive numbers for all fields.");
return;
}
// 1. Calculate Residual Value in Dollars
var residualValue = price * resPercent;
// 2. Adjusted Capitalized Cost
var adjCapCost = price – down;
// 3. Monthly Depreciation Fee
var depreciation = (adjCapCost – residualValue) / term;
if (depreciation < 0) depreciation = 0;
// 4. Monthly Finance Fee (Rent Charge)
var rentCharge = (adjCapCost + residualValue) * mf;
// 5. Subtotal Base Payment
var basePayment = depreciation + rentCharge;
// 6. Monthly Tax
var monthlyTax = basePayment * taxRate;
// 7. Total Monthly Payment
var totalMonthly = basePayment + monthlyTax;
// Display Results
document.getElementById('monthlyTotal').innerText = '$' + totalMonthly.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('depreciationPart').innerText = '$' + depreciation.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('resultArea').style.display = 'block';
}
How to Calculate a Car Lease Payment
Understanding how a car lease payment is calculated can save you thousands of dollars at the dealership. Unlike a traditional car loan, where you pay for the entire value of the vehicle plus interest, a lease payment is primarily based on the vehicle's depreciation during the time you drive it.
Key Lease Terms You Must Know
Gross Capitalized Cost: The total price of the vehicle, including the negotiated price and any extra fees or insurance products.
Residual Value: This is the estimated value of the car at the end of the lease. It is set by the bank and is non-negotiable. A higher residual value results in a lower monthly payment.
Money Factor: This represents the interest rate on the lease. To convert a money factor to a standard APR, multiply it by 2,400. (Example: 0.00125 x 2400 = 3% APR).
Cap Cost Reduction: Anything that lowers the amount being financed, such as a down payment, trade-in, or manufacturer rebates.
The Car Lease Formula
The calculation is broken into three main parts:
Depreciation Fee: (Adjusted Cap Cost – Residual Value) ÷ Lease Term
Let's say you negotiate a car price to $30,000 for a 36-month lease. The residual value is 60% ($18,000). You put $2,000 down, leaving an adjusted cap cost of $28,000. Your money factor is 0.0015.