How to Calculate Implicit Interest Rate in a Lease
by
Car Lease Calculator
Estimate your monthly lease payment before visiting the dealership.
24 Months
36 Months
48 Months
60 Months
Estimated Monthly Payment$0.00
Residual Value:
Monthly Depreciation:
Monthly Rent Charge:
Monthly Tax:
Understanding Your Car Lease Calculation
Leasing a car is different from traditional financing. Instead of paying for the whole vehicle, you are essentially paying for the depreciation of the car over the term of the lease, plus interest (the "Money Factor") and taxes.
Key Terms Explained:
Gross Capitalized Cost: This is the "Negotiated Price" of the vehicle. Always negotiate the price just as if you were buying it.
Residual Value: The estimated value of the car at the end of the lease. High residual values lead to lower monthly payments.
Money Factor: The interest rate on a lease. To find the equivalent APR, multiply the money factor by 2,400. (e.g., 0.0025 * 2400 = 6% APR).
Capitalized Cost Reduction: This includes your down payment, trade-in value, and any rebates that lower the amount being financed.
Lease Calculation Example:
Imagine a car with an MSRP of $35,000 and a Residual Value of 60% ($21,000). If you negotiate the price to $32,000 and put $2,000 down, your Adjusted Cap Cost is $30,000. Over 36 months, you must pay off the $9,000 difference ($30,000 – $21,000), which is $250/month in depreciation alone. Interest and taxes are then added to this base amount.
function calculateLease() {
// Get Input Values
var msrp = parseFloat(document.getElementById("msrp").value);
var salePrice = parseFloat(document.getElementById("salePrice").value);
var downPayment = parseFloat(document.getElementById("downPayment").value) || 0;
var tradeIn = parseFloat(document.getElementById("tradeIn").value) || 0;
var leaseTerm = parseFloat(document.getElementById("leaseTerm").value);
var residualPercent = parseFloat(document.getElementById("residualPercent").value);
var moneyFactor = parseFloat(document.getElementById("moneyFactor").value);
var salesTax = parseFloat(document.getElementById("salesTax").value);
// Validate inputs
if (isNaN(msrp) || isNaN(salePrice) || isNaN(leaseTerm) || isNaN(residualPercent) || isNaN(moneyFactor)) {
alert("Please enter valid numerical values.");
return;
}
// 1. Calculate Residual Value
var residualValue = msrp * (residualPercent / 100);
// 2. Calculate Adjusted Capitalized Cost
var adjustedCapCost = salePrice – (downPayment + tradeIn);
// 3. Calculate Monthly Depreciation
var totalDepreciation = adjustedCapCost – residualValue;
// Safety check for negative depreciation
if (totalDepreciation < 0) {
totalDepreciation = 0;
}
var monthlyDepreciation = totalDepreciation / leaseTerm;
// 4. Calculate Monthly Rent Charge
// Formula: (Adjusted Cap Cost + Residual Value) * Money Factor
var monthlyRentCharge = (adjustedCapCost + residualValue) * moneyFactor;
// 5. Calculate Subtotal and Tax
var monthlySubtotal = monthlyDepreciation + monthlyRentCharge;
var monthlyTaxAmount = monthlySubtotal * (salesTax / 100);
// 6. Total Monthly Payment
var totalMonthlyPayment = monthlySubtotal + monthlyTaxAmount;
// Display Results
document.getElementById("leaseResult").style.display = "block";
document.getElementById("monthlyPaymentOutput").innerHTML = "$" + totalMonthlyPayment.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("resValDollar").innerHTML = "$" + residualValue.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("monthlyDepr").innerHTML = "$" + monthlyDepreciation.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("monthlyRent").innerHTML = "$" + monthlyRentCharge.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("monthlyTax").innerHTML = "$" + monthlyTaxAmount.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
}