Lease Interest Rate Calculator

Lease Interest Rate Calculator & Analysis :root { –primary-color: #004a99; –success-color: #28a745; –background-color: #f8f9fa; –text-color: #333; –border-color: #ccc; –card-background: #fff; –shadow: 0 2px 5px rgba(0,0,0,0.1); } body { font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; background-color: var(–background-color); color: var(–text-color); margin: 0; padding: 0; line-height: 1.6; } .container { max-width: 1000px; margin: 20px auto; padding: 20px; background-color: var(–card-background); box-shadow: var(–shadow); border-radius: 8px; } header { text-align: center; margin-bottom: 30px; padding-bottom: 20px; border-bottom: 1px solid var(–border-color); } header h1 { color: var(–primary-color); margin-bottom: 10px; } .sub-heading { font-size: 1.1em; color: #666; margin-bottom: 20px; } .loan-calc-container { padding: 25px; border: 1px solid var(–border-color); border-radius: 8px; margin-bottom: 30px; background-color: var(–card-background); } .input-group { margin-bottom: 20px; text-align: left; } .input-group label { display: block; margin-bottom: 8px; font-weight: bold; color: var(–primary-color); } .input-group input[type="number"], .input-group input[type="text"], .input-group select { width: calc(100% – 22px); padding: 10px; border: 1px solid var(–border-color); border-radius: 4px; box-sizing: border-box; font-size: 1em; } .input-group input[type="number"]:focus, .input-group input[type="text"]:focus, .input-group select:focus { border-color: var(–primary-color); outline: none; box-shadow: 0 0 0 2px rgba(0, 74, 153, 0.2); } .input-group .helper-text { font-size: 0.85em; color: #555; margin-top: 5px; } .error-message { color: red; font-size: 0.85em; margin-top: 5px; min-height: 1.2em; /* Prevent layout shifts */ } .button-group { display: flex; justify-content: space-between; margin-top: 25px; gap: 10px; } .button-group button { padding: 12px 20px; border: none; border-radius: 5px; cursor: pointer; font-size: 1em; font-weight: bold; transition: background-color 0.3s ease, transform 0.2s ease; } .button-group .calculate-button { background-color: var(–primary-color); color: white; flex-grow: 1; } .button-group .calculate-button:hover { background-color: #003b7d; transform: translateY(-1px); } .button-group .reset-button, .button-group .copy-button { background-color: #6c757d; color: white; } .button-group .reset-button:hover, .button-group .copy-button:hover { background-color: #5a6268; transform: translateY(-1px); } #results { margin-top: 30px; padding: 25px; border: 1px solid var(–border-color); border-radius: 8px; background-color: var(–card-background); text-align: center; } #results h2 { color: var(–primary-color); margin-bottom: 15px; font-size: 1.5em; } .result-item { margin-bottom: 15px; padding: 15px; border-radius: 5px; border: 1px solid var(–border-color); } .result-item-label { font-weight: bold; color: #555; display: block; margin-bottom: 5px; } .primary-result { font-size: 2.2em; font-weight: bold; color: var(–success-color); background-color: rgba(40, 167, 69, 0.1); padding: 20px; border-radius: 8px; border: 1px dashed var(–success-color); margin-bottom: 20px; } .intermediate-results .result-item { background-color: var(–background-color); border-style: dashed; } .formula-explanation { font-size: 0.9em; color: #777; margin-top: 15px; font-style: italic; } #chartContainer { text-align: center; margin-top: 30px; padding: 20px; border: 1px solid var(–border-color); border-radius: 8px; background-color: var(–card-background); } #chartContainer canvas { max-width: 100%; height: auto; } #chartContainer .chart-caption { font-size: 0.9em; color: #777; margin-top: 10px; } .table-container { margin-top: 30px; overflow-x: auto; padding: 20px; border: 1px solid var(–border-color); border-radius: 8px; background-color: var(–card-background); } .table-container caption { font-size: 1.2em; font-weight: bold; color: var(–primary-color); margin-bottom: 15px; caption-side: top; text-align: center; } .table-container table { width: 100%; border-collapse: collapse; margin-top: 15px; } .table-container th, .table-container td { padding: 12px 15px; border: 1px solid var(–border-color); text-align: right; } .table-container th { background-color: var(–primary-color); color: white; font-weight: bold; } .table-container td:first-child { text-align: left; font-weight: bold; } .table-container tr:nth-child(even) { background-color: var(–background-color); } article { margin-top: 40px; padding: 30px; background-color: var(–card-background); border-radius: 8px; box-shadow: var(–shadow); } article h2 { color: var(–primary-color); border-bottom: 2px solid var(–primary-color); padding-bottom: 8px; margin-top: 30px; margin-bottom: 15px; } article h3 { color: var(–primary-color); margin-top: 20px; margin-bottom: 10px; } article p, article ul, article ol { margin-bottom: 15px; font-size: 1.05em; } article ul, article ol { padding-left: 30px; } article li { margin-bottom: 8px; } .faq-item { margin-bottom: 15px; padding: 15px; border: 1px dashed var(–border-color); border-radius: 5px; background-color: var(–background-color); } .faq-item strong { color: var(–primary-color); display: block; margin-bottom: 5px; } .faq-item p { margin-bottom: 0; } .internal-links-section { margin-top: 30px; padding: 20px; border: 1px solid var(–border-color); border-radius: 8px; background-color: var(–card-background); } .internal-links-section h3 { margin-top: 0; margin-bottom: 15px; color: var(–primary-color); } .internal-links-section ul { list-style: none; padding: 0; } .internal-links-section li { margin-bottom: 10px; } .internal-links-section a { color: var(–primary-color); text-decoration: none; font-weight: bold; } .internal-links-section a:hover { text-decoration: underline; } .internal-links-section p { font-size: 0.9em; color: #666; margin-top: 5px; } /* Responsive adjustments */ @media (max-width: 768px) { .container { margin: 10px; padding: 15px; } .button-group { flex-direction: column; align-items: stretch; } .button-group button { width: 100%; } }

Lease Interest Rate Calculator

Calculate, understand, and compare lease interest rates easily.

The total cost of the item being leased.
The estimated value of the asset at the end of the lease term.
The duration of the lease agreement in months.
An upfront payment made at the start of the lease (optional).
Any one-time fees associated with setting up the lease.

Lease Interest Rate Results

The effective lease interest rate is calculated using a financial formula that approximates the rate based on the lease payment, capital cost, residual value, term, and upfront costs.
Total Lease Cost (Excl. Residual)
Total Finance Amount
Estimated Monthly Payment
Capital Cost Reduction
Monthly Breakdown: Principal vs. Interest Component
Lease Amortization Schedule (Simplified)
Month Starting Balance Interest Paid Principal Paid Ending Balance

What is Lease Interest Rate?

The lease interest rate, often referred to as the money factor or implied interest rate, is a crucial component of any lease agreement. It represents the cost of borrowing the money used to finance the leased asset over the lease term. Understanding this rate is vital for consumers and businesses alike, as it directly impacts the total cost of leasing a vehicle, equipment, or property. It's essentially the lender's profit margin and the cost you bear for using their capital. Unlike a traditional loan interest rate, the lease interest rate is often expressed as a "money factor," which is a small decimal number. To convert this money factor to an approximate Annual Percentage Rate (APR), you typically multiply it by 2400. For example, a money factor of 0.00125 would equate to an approximate APR of 3% (0.00125 * 2400 = 3%).

Who should use it: Anyone considering leasing an asset, whether it's a car, commercial equipment, or even real estate, should pay close attention to the lease interest rate. This includes individual consumers seeking a new vehicle, small business owners looking to acquire necessary machinery, and larger corporations managing fleets or property portfolios. A lower lease interest rate means lower overall borrowing costs, leading to more affordable monthly payments and a reduced total cost over the lease's life. Conversely, a higher rate inflates the cost.

Common misconceptions: A frequent misconception is that the lease interest rate is the only cost to consider. In reality, lease agreements involve various other fees, residual values, and potential penalties that contribute to the overall financial picture. Another misunderstanding is the direct conversion from money factor to APR; while multiplying by 2400 is a common shortcut, it's an approximation, and the true effective rate can vary slightly. Lastly, some believe all lease rates are negotiable; while rates can sometimes be influenced, they are often tied to market conditions and the lessee's creditworthiness.

Lease Interest Rate Formula and Mathematical Explanation

Calculating the exact lease interest rate involves an iterative process because the monthly payment itself is dependent on the interest rate. However, we can approximate the lease interest rate using financial formulas. A common approach involves calculating the Net Capitalized Cost (the price of the asset after down payments, trade-in allowances, and other credits) and the residual value, then using these to estimate the total depreciation and financing charges. The formula for the approximate APR is often derived from:

$$ \text{APR} \approx \left( \frac{\text{Money Factor} \times \text{Lease Amount} \times \text{Lease Term}}{\text{Capital Cost Reduction}} \right) \times 2400 $$

A more accurate method uses the internal rate of return (IRR) concept, where we solve for the rate 'r' in the following equation:

$$ \sum_{t=1}^{n} \frac{P_t}{(1+r)^t} = \text{Net Capitalized Cost} $$ Where:

  • $P_t$ is the payment in period t (monthly payment minus interest portion related to residual value financing)
  • $n$ is the number of periods (months)
  • $r$ is the periodic interest rate (monthly APR)
  • Net Capitalized Cost = (Lease Amount – Down Payment – Fees + Acquisition Fee – Residual Value)

For practical purposes, financial calculators and software use algorithms to find this 'r'. Our calculator uses a financial function that approximates this iterative process to provide an effective lease interest rate.

Variables Explained:

Variable Meaning Unit Typical Range
Lease Amount The total agreed-upon price or value of the asset being leased. Currency ($) $5,000 – $100,000+
Residual Value The estimated market value of the asset at the end of the lease term. Currency ($) 20% – 60% of MSRP
Lease Term The total duration of the lease agreement. Months 12 – 60 months
Down Payment An upfront payment reducing the financed amount. Currency ($) $0 – 20%+
Upfront Fees One-time charges like acquisition fees, documentation fees, etc. Currency ($) $0 – $1,500+
Money Factor A decimal representing the monthly finance charge. Decimal 0.00050 – 0.00250+
APR (Annual Percentage Rate) The annualized cost of borrowing, expressed as a percentage. % 2% – 10%+
Estimated Monthly Payment The regular payment required to service the lease. Currency ($) Varies widely

Practical Examples (Real-World Use Cases)

Example 1: Leasing a New Car

Sarah is looking to lease a new electric vehicle. The car's MSRP is $45,000. The dealer offers a lease with a residual value of 50% after 36 months. The capitalized cost (price after negotiation and incentives) is $42,000. Sarah plans to make a down payment of $2,000 and pay $700 in upfront fees (acquisition, documentation).

  • Inputs:
  • Lease Amount: $42,000
  • Residual Value: $22,500 (50% of $45,000 MSRP, assuming this is the basis)
  • Lease Term: 36 Months
  • Down Payment: $2,000
  • Upfront Fees: $700

Using the calculator, we input these values. The calculator determines the total depreciation ($42,000 – $22,500 = $19,500). It then calculates the total amount to be financed ($42,000 – $2,000 down payment – $700 fees = $39,300). With these figures, the calculator approximates the money factor and converts it to an effective lease interest rate (APR). Let's say the calculator outputs an estimated monthly payment of $650 and an effective APR of 4.5%.

Interpretation: Sarah's total cost over 36 months will be her down payment ($2,000) + fees ($700) + total monthly payments ($650 x 36 = $23,400), plus the residual value ($22,500) if she chooses to buy it out. The 4.5% APR reflects the cost of financing the depreciation ($19,500) and any remaining balance over the term.

Example 2: Leasing Business Equipment

A small bakery needs a new commercial oven. The price of the oven is $15,000. The lease term is 48 months, with a residual value of $3,000. There are no down payments, but there's an upfront processing fee of $300.

  • Inputs:
  • Lease Amount: $15,000
  • Residual Value: $3,000
  • Lease Term: 48 Months
  • Down Payment: $0
  • Upfront Fees: $300

The calculator computes the depreciation ($15,000 – $3,000 = $12,000). The total financed amount is $15,000 – $0 – $300 = $14,700. Based on these inputs, the calculator might estimate a monthly payment of $375 and an effective lease interest rate of 6.2%.

Interpretation: The bakery will pay $300 upfront and $375 per month for 48 months ($18,000 total). The 6.2% APR indicates the financing cost associated with the $12,000 depreciation and the remaining balance. This helps the bakery determine if the operational benefits of the new oven justify the total leasing cost. This is a key aspect of understanding your lease interest rate calculator inputs.

How to Use This Lease Interest Rate Calculator

  1. Enter Lease Amount: Input the total agreed-upon price or value of the asset you intend to lease. This is often the vehicle's MSRP or the equipment's purchase price.
  2. Input Residual Value: Provide the estimated value of the asset at the end of the lease term. This is usually expressed as a percentage of the MSRP or a fixed dollar amount.
  3. Specify Lease Term: Enter the duration of the lease agreement in months. Common terms range from 24 to 60 months.
  4. Add Down Payment: If you plan to make an upfront payment, enter that amount. This reduces the total amount financed and can lower your monthly payments.
  5. Include Upfront Fees: Sum up all one-time fees associated with the lease, such as acquisition fees, documentation fees, or initial taxes.
  6. Click Calculate: Press the "Calculate Rate" button.

How to read results: The calculator will display the primary highlighted result, which is the estimated Annual Percentage Rate (APR). This is your most direct indicator of the cost of financing. It will also show key intermediate values: the total lease cost (depreciation), the total amount being financed (after down payments and fees), and the estimated monthly payment. The simplified amortization table shows how each payment is allocated between interest and principal (depreciation) over the lease term.

Decision-making guidance: Compare the calculated APR to other financing options or loans you might qualify for. A lower APR generally signifies a better deal. Use the estimated monthly payment and total cost to assess affordability within your budget. If the results seem unfavorable, consider negotiating the lease amount, down payment, fees, or residual value. Understanding your lease interest rate is crucial for making informed financial decisions.

Key Factors That Affect Lease Interest Rate Results

  1. Capitalized Cost (Lease Amount): The negotiated price of the vehicle or asset significantly impacts the lease. A lower capitalized cost reduces the total amount financed, which in turn can lower the interest charges and the effective lease interest rate. This is often the most negotiable aspect.
  2. Residual Value: This is the predicted value of the asset at the end of the lease. A higher residual value means less depreciation to finance, leading to lower monthly payments and potentially a lower effective interest rate. Manufacturers often set these, but market conditions can influence them.
  3. Credit Score: Your creditworthiness is paramount. A higher credit score typically grants access to lower money factors (and thus lower APRs), as lenders perceive less risk. Poor credit will result in higher rates. This is a direct reflection of perceived risk.
  4. Lease Term: Longer lease terms usually mean lower monthly payments, but you often end up paying more interest over the life of the lease. The effective APR might remain similar, but the total financing cost increases. Shortening the term often increases the monthly payment but reduces total interest paid.
  5. Market Interest Rates: Like any loan, lease financing is influenced by prevailing economic conditions and the central bank's interest rate policies. When general interest rates rise, lease money factors and APRs tend to follow suit. This impacts the cost of funds for lenders.
  6. Upfront Payments (Down Payment & Fees): While a higher down payment or paying extra fees upfront reduces the amount financed and the monthly payment, it doesn't always significantly lower the quoted money factor or APR. However, it does decrease the overall cash outlay required to service the depreciation portion of the lease. Be mindful that high upfront costs can sometimes mask a less-than-ideal rate.
  7. Money Factor: This is the direct expression of the finance charge used by lessors. It's a small decimal (e.g., 0.00150). A lower money factor directly translates to a lower monthly payment and a lower effective lease interest rate (APR ≈ Money Factor * 2400). Negotiating the money factor is key.

Frequently Asked Questions (FAQ)

Q: What's the difference between a money factor and an APR for leases?

A: The money factor is a small decimal representing the monthly finance charge, commonly used in lease agreements. The APR (Annual Percentage Rate) is the annualized cost of borrowing, expressed as a percentage. While often approximated by multiplying the money factor by 2400, the APR is a more universally understood metric for comparing borrowing costs. Our lease interest rate calculator provides both approximations.

Q: Can I negotiate the lease interest rate (money factor)?

A: Yes, the money factor is often negotiable, especially the "buy rate" (the base rate offered by the finance company). Dealerships may mark this up. Your credit score heavily influences the rate you'll be offered. A good credit score gives you leverage for a lower money factor.

Q: What happens if I exceed the mileage limit on my lease?

Exceeding the mileage limit results in per-mile charges at the end of the lease, which can be substantial. These charges are separate from the interest rate but add to your total cost. Always choose a lease term and mileage allowance that fits your driving habits.

Q: Is a higher residual value always better?

A higher residual value generally leads to lower monthly payments because you're financing less depreciation. However, it also means the asset will be worth less at lease end, potentially leaving you with less equity if you decide to purchase it or if its market value exceeds the residual.

Q: How do upfront fees affect my lease interest rate?

Upfront fees (like acquisition fees, documentation fees) increase your initial cash outlay and the total amount financed. While they don't directly change the *money factor* itself, they increase the total cost of the lease and affect the overall yield for the lender. Some fees might be negotiable or rolled into the capitalized cost.

Q: Can I use the calculator for any type of lease?

This calculator is primarily designed for leases where a residual value is a key factor, such as vehicles and equipment. It may not perfectly apply to complex real estate leases or finance leases without residuals. Always consult your lease agreement.

Q: What is the 'Capital Cost Reduction' shown in the results?

Capital Cost Reduction is the total reduction applied to the gross capitalized cost (the initial price) before calculating depreciation. It includes your down payment, trade-in value, and any rebates or incentives applied directly to the price. It lowers the amount you finance.

Q: Why is the calculated APR an approximation?

Lease payments are calculated iteratively. The monthly payment depends on the interest rate, and the interest portion depends on the monthly payment. Finding the exact rate requires complex financial calculations or iterative methods. Our calculator provides a highly accurate approximation based on standard financial formulas and common market practices for estimating the lease interest rate.

var chartInstance = null; function formatCurrency(amount) { return "$" + amount.toFixed(2).replace(/\d(?=(\d{3})+\.)/g, '$&,'); } function formatRate(rate) { return rate.toFixed(2) + "%"; } function validateInput(id, errorId, min, max, required = true) { var value = parseFloat(document.getElementById(id).value); var errorElement = document.getElementById(errorId); errorElement.textContent = "; // Clear previous error if (required && (isNaN(value) || document.getElementById(id).value.trim() === ")) { errorElement.textContent = 'This field is required.'; return false; } if (!isNaN(value)) { if (min !== undefined && value max) { errorElement.textContent = `Value cannot be greater than ${formatCurrency(max)}.`; return false; } } if (id === 'leaseTermMonths' && !isNaN(value) && value <= 0) { errorElement.textContent = 'Lease term must be positive.'; return false; } return true; } function calculateLeaseInterest() { // Clear previous errors document.getElementById('leaseAmountError').textContent = ''; document.getElementById('residualValueError').textContent = ''; document.getElementById('leaseTermMonthsError').textContent = ''; document.getElementById('downPaymentError').textContent = ''; document.getElementById('feesError').textContent = ''; // Validate inputs var isValid = true; isValid &= validateInput('leaseAmount', 'leaseAmountError', 0); isValid &= validateInput('residualValue', 'residualValueError', 0); isValid &= validateInput('leaseTermMonths', 'leaseTermMonthsError', 1); // Term must be at least 1 month isValid &= validateInput('downPayment', 'downPaymentError', 0); isValid &= validateInput('fees', 'feesError', 0); var leaseAmount = parseFloat(document.getElementById('leaseAmount').value); var residualValue = parseFloat(document.getElementById('residualValue').value); var leaseTermMonths = parseInt(document.getElementById('leaseTermMonths').value); var downPayment = parseFloat(document.getElementById('downPayment').value); var fees = parseFloat(document.getElementById('fees').value); // Check for specific invalid combinations if (leaseAmount = leaseAmount) { document.getElementById('downPaymentError').textContent = 'Down payment and fees cannot exceed the lease amount.'; isValid = false; } if (!isValid) { clearResults(); return; } // Calculations var capitalCost = leaseAmount; // Gross Capitalized Cost var capitalCostReduction = downPayment + fees; // Total reductions var netCapitalizedCost = capitalCost – capitalCostReduction; // Net Cap Cost var depreciation = capitalCost – residualValue; // Total depreciation to be financed // Estimate monthly payment and money factor using an iterative approach or financial function approximation // This is a simplified approximation. Real-world calculators use more complex algorithms (like IRR solvers). // Simplified approximation for Monthly Payment (based on depreciation and financing over term) // This formula approximates the payment part related to depreciation and cost of money. // It's not a perfect IRR, but a common estimation method. var estimatedMonthlyPayment; var moneyFactor; // Iterative approach to find Money Factor and Monthly Payment var lowMF = 0.00001; var highMF = 0.01; // A very high money factor to ensure the range covers possibilities var iterations = 100; // Number of iterations for binary search for (var i = 0; i netCapitalizedCost) { // Our hypothetical payment is too high for this MF, or MF is too low lowMF = currentMF; } else { // Our hypothetical payment is too low for this MF, or MF is too high highMF = currentMF; } } catch (e) { // Handle potential math errors like division by zero if monthlyRate is 0 highMF = 0.001; // Reset to a smaller range if issues occur } } moneyFactor = (lowMF + highMF) / 2; var monthlyRate = moneyFactor; // Calculate the estimated monthly payment using the found money factor // This uses the standard lease payment formula structure var principalForPayment = netCapitalizedCost – residualValue; // The portion being paid down var financingCostFactor = (1 – Math.pow(1 + monthlyRate, -leaseTermMonths)) / monthlyRate; var depreciationPayment = principalForPayment / leaseTermMonths; // Simplified base payment // More accurate PMT calculation for leases: estimatedMonthlyPayment = (netCapitalizedCost – residualValue) / leaseTermMonths + (netCapitalizedCost * monthlyRate); // Linear approx. // Using financial formula for PMT (solving for PMT given PV, rate, nper) estimatedMonthlyPayment = netCapitalizedCost * (monthlyRate * Math.pow(1 + monthlyRate, leaseTermMonths)) / (Math.pow(1 + monthlyRate, leaseTermMonths) – 1) – residualValue * monthlyRate / (1 – Math.pow(1 + monthlyRate, -leaseTermMonths)); // Let's use a standard approximation that's often employed: // PMT = (PV – FV/(1+r)^n) * r / (1 – (1+r)^-n) var effectivePV = netCapitalizedCost; var effectiveFV = residualValue; var nper = leaseTermMonths; if (monthlyRate > 0) { estimatedMonthlyPayment = (effectivePV – effectiveFV / Math.pow(1 + monthlyRate, nper)) * monthlyRate / (1 – Math.pow(1 + monthlyRate, -nper)); } else { estimatedMonthlyPayment = (effectivePV – effectiveFV) / nper; // Simple division if rate is 0 } var effectiveAPR = moneyFactor * 2400; // Intermediate Results var totalLeaseCostExclResidual = depreciation; // This is the total amount paid towards the asset's value loss var totalFinanceAmount = netCapitalizedCost; // The amount that needs to be financed over time // Update results display document.getElementById('effectiveRateDisplay').textContent = formatRate(effectiveAPR); document.getElementById('totalLeaseCost').textContent = formatCurrency(totalLeaseCostExclResidual); document.getElementById('totalFinanceAmount').textContent = formatCurrency(totalFinanceAmount); document.getElementById('estimatedMonthlyPayment').textContent = formatCurrency(estimatedMonthlyPayment); document.getElementById('capitalCostReduction').textContent = formatCurrency(capitalCostReduction); // Update table and chart updateLeaseSchedule(netCapitalizedCost, residualValue, leaseTermMonths, monthlyRate, estimatedMonthlyPayment); updateChart(netCapitalizedCost, residualValue, leaseTermMonths, monthlyRate, estimatedMonthlyPayment); document.getElementById('leaseScheduleTableCaption').textContent = `Lease Amortization Schedule (${leaseTermMonths} Months)`; } function updateLeaseSchedule(startBalance, residualValue, term, monthlyRate, monthlyPayment) { var tableBody = document.getElementById('leaseScheduleTable').getElementsByTagName('tbody')[0]; tableBody.innerHTML = "; // Clear existing rows var balance = startBalance; var principalPaidTotal = 0; var interestPaidTotal = 0; for (var i = 1; i <= term; i++) { var interestPayment = balance * monthlyRate; var principalPayment = monthlyPayment – interestPayment; // Adjust last payment to ensure ending balance is residual value if (i === term) { principalPayment = balance – residualValue; interestPayment = monthlyPayment – principalPayment; // Ensure total payment matches if (interestPayment < 0) { // Handle cases where payment might not cover interest + desired principal interestPayment = 0; // Or re-evaluate monthly payment calculation logic principalPayment = monthlyPayment; } } // Ensure balance doesn't go below residual value due to calculation inaccuracies if (balance – principalPayment < residualValue && i < term) { principalPayment = balance – residualValue; interestPayment = monthlyPayment – principalPayment; if (interestPayment < 0) interestPayment = 0; // Prevent negative interest } balance -= principalPayment; principalPaidTotal += principalPayment; interestPaidTotal += interestPayment; if (balance < residualValue && i < term) { balance = residualValue; // Ensure it doesn't dip below residual prematurely } var row = tableBody.insertRow(); row.insertCell(0).textContent = i; row.insertCell(1).textContent = formatCurrency(balance + principalPayment); // Starting balance for the month row.insertCell(2).textContent = formatCurrency(interestPayment); row.insertCell(3).textContent = formatCurrency(principalPayment); row.insertCell(4).textContent = formatCurrency(balance); } // Add a footer row for totals if needed, or summary in results } function updateChart(startBalance, residualValue, term, monthlyRate, monthlyPayment) { var ctx = document.getElementById('leaseChart').getContext('2d'); if (chartInstance) { chartInstance.destroy(); } var labels = []; var principalData = []; var interestData = []; var balance = startBalance; for (var i = 1; i <= term; i++) { labels.push('Month ' + i); var interestPayment = balance * monthlyRate; var principalPayment = monthlyPayment – interestPayment; if (i === term) { principalPayment = balance – residualValue; interestPayment = monthlyPayment – principalPayment; if (interestPayment < 0) interestPayment = 0; } if (balance – principalPayment < residualValue && i < term) { principalPayment = balance – residualValue; interestPayment = monthlyPayment – principalPayment; if (interestPayment < 0) interestPayment = 0; } balance -= principalPayment; if (balance < residualValue && i < term) { balance = residualValue; } principalData.push(principalPayment); interestData.push(interestPayment); } chartInstance = new Chart(ctx, { type: 'bar', data: { labels: labels, datasets: [{ label: 'Principal Paid', data: principalData, backgroundColor: 'rgba(0, 74, 153, 0.6)', borderColor: 'rgba(0, 74, 153, 1)', borderWidth: 1 }, { label: 'Interest Paid', data: interestData, backgroundColor: 'rgba(40, 167, 69, 0.6)', borderColor: 'rgba(40, 167, 69, 1)', borderWidth: 1 }] }, options: { responsive: true, maintainAspectRatio: true, scales: { y: { beginAtZero: true, ticks: { callback: function(value) { if (value % 1000 === 0) { return formatCurrency(value); } return ''; } } } }, plugins: { tooltip: { callbacks: { label: function(context) { var label = context.dataset.label || ''; if (label) { label += ': '; } if (context.parsed.y !== null) { label += formatCurrency(context.parsed.y); } return label; } } } } } }); } function copyResults() { var mainResult = document.getElementById('effectiveRateDisplay').textContent; var totalLeaseCost = document.getElementById('totalLeaseCost').textContent; var totalFinanceAmount = document.getElementById('totalFinanceAmount').textContent; var estimatedMonthlyPayment = document.getElementById('estimatedMonthlyPayment').textContent; var capitalCostReduction = document.getElementById('capitalCostReduction').textContent; var leaseAmount = document.getElementById('leaseAmount').value; var residualValue = document.getElementById('residualValue').value; var leaseTermMonths = document.getElementById('leaseTermMonths').value; var downPayment = document.getElementById('downPayment').value; var fees = document.getElementById('fees').value; var assumptions = `Assumptions:\nLease Amount: $${leaseAmount}\nResidual Value: $${residualValue}\nLease Term: ${leaseTermMonths} months\nDown Payment: $${downPayment}\nUpfront Fees: $${fees}`; var resultsText = `Lease Interest Rate Results:\n\nEffective APR: ${mainResult}\nEstimated Monthly Payment: ${estimatedMonthlyPayment}\nTotal Lease Cost (Excl. Residual): ${totalLeaseCost}\nTotal Finance Amount: ${totalFinanceAmount}\nCapital Cost Reduction: ${capitalCostReduction}\n\n${assumptions}`; navigator.clipboard.writeText(resultsText).then(function() { // Success feedback (optional) var copyButton = document.querySelector('.copy-button'); var originalText = copyButton.textContent; copyButton.textContent = 'Copied!'; setTimeout(function() { copyButton.textContent = originalText; }, 2000); }).catch(function(err) { console.error('Failed to copy text: ', err); alert('Failed to copy results. Please copy manually.'); }); } function resetCalculator() { document.getElementById('leaseAmount').value = ''; document.getElementById('residualValue').value = ''; document.getElementById('leaseTermMonths').value = ''; document.getElementById('downPayment').value = '0'; document.getElementById('fees').value = '0'; clearResults(); // Clear errors document.getElementById('leaseAmountError').textContent = ''; document.getElementById('residualValueError').textContent = ''; document.getElementById('leaseTermMonthsError').textContent = ''; document.getElementById('downPaymentError').textContent = ''; document.getElementById('feesError').textContent = ''; } function clearResults() { document.getElementById('effectiveRateDisplay').textContent = '–'; document.getElementById('totalLeaseCost').textContent = '–'; document.getElementById('totalFinanceAmount').textContent = '–'; document.getElementById('estimatedMonthlyPayment').textContent = '–'; document.getElementById('capitalCostReduction').textContent = '–'; var tableBody = document.getElementById('leaseScheduleTable').getElementsByTagName('tbody')[0]; tableBody.innerHTML = ''; if (chartInstance) { chartInstance.destroy(); chartInstance = null; } document.getElementById('leaseChart').getContext('2d').clearRect(0,0, document.getElementById('leaseChart').width, document.getElementById('leaseChart').height); // Clear canvas } // Initial calculation on load with default values (if any) document.addEventListener('DOMContentLoaded', function() { // Optionally set some sensible defaults or run calculation if inputs are pre-filled // resetCalculator(); // Call reset to ensure clean state or set defaults // calculateLeaseInterest(); // Uncomment if you want calculation on page load with defaults });

Leave a Comment