.roi-calculator-container {
font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
max-width: 800px;
margin: 0 auto;
padding: 20px;
background: #f9f9f9;
border: 1px solid #e0e0e0;
border-radius: 8px;
box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}
.roi-calc-header {
text-align: center;
margin-bottom: 25px;
}
.roi-calc-header h2 {
color: #2c3e50;
margin: 0;
}
.roi-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
}
@media (max-width: 600px) {
.roi-grid {
grid-template-columns: 1fr;
}
}
.roi-input-group {
margin-bottom: 15px;
}
.roi-input-group label {
display: block;
font-weight: 600;
margin-bottom: 5px;
color: #555;
font-size: 0.9rem;
}
.roi-input-group input {
width: 100%;
padding: 10px;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 1rem;
box-sizing: border-box;
}
.roi-input-group input:focus {
border-color: #3498db;
outline: none;
}
.roi-section-title {
grid-column: 1 / -1;
font-size: 1.1rem;
font-weight: bold;
color: #2980b9;
border-bottom: 2px solid #2980b9;
padding-bottom: 5px;
margin-top: 10px;
margin-bottom: 10px;
}
.roi-btn-container {
grid-column: 1 / -1;
text-align: center;
margin-top: 20px;
}
.roi-calculate-btn {
background-color: #27ae60;
color: white;
padding: 12px 30px;
font-size: 1.1rem;
border: none;
border-radius: 5px;
cursor: pointer;
transition: background 0.3s;
}
.roi-calculate-btn:hover {
background-color: #219150;
}
.roi-results-section {
grid-column: 1 / -1;
background: #fff;
padding: 20px;
border-radius: 5px;
border: 1px solid #ddd;
margin-top: 20px;
display: none; /* Hidden by default */
}
.roi-result-row {
display: flex;
justify-content: space-between;
padding: 10px 0;
border-bottom: 1px solid #eee;
}
.roi-result-row:last-child {
border-bottom: none;
}
.roi-result-label {
font-weight: 500;
color: #444;
}
.roi-result-value {
font-weight: 700;
color: #2c3e50;
}
.roi-highlight {
color: #27ae60;
font-size: 1.2rem;
}
.roi-neg {
color: #c0392b;
}
.roi-article {
max-width: 800px;
margin: 40px auto;
font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
line-height: 1.6;
color: #333;
}
.roi-article h2 {
color: #2c3e50;
border-bottom: 2px solid #ecf0f1;
padding-bottom: 10px;
margin-top: 30px;
}
.roi-article h3 {
color: #34495e;
margin-top: 25px;
}
.roi-article p {
margin-bottom: 15px;
}
.roi-article ul {
margin-bottom: 20px;
}
.roi-article li {
margin-bottom: 8px;
}
function calculateRentalROI() {
// Get Input Values
var purchasePrice = parseFloat(document.getElementById('purchasePrice').value) || 0;
var downPaymentPercent = parseFloat(document.getElementById('downPayment').value) || 0;
var interestRate = parseFloat(document.getElementById('interestRate').value) || 0;
var loanTerm = parseFloat(document.getElementById('loanTerm').value) || 0;
var closingCosts = parseFloat(document.getElementById('closingCosts').value) || 0;
var monthlyRent = parseFloat(document.getElementById('monthlyRent').value) || 0;
var annualTax = parseFloat(document.getElementById('propertyTax').value) || 0;
var annualInsurance = parseFloat(document.getElementById('insurance').value) || 0;
var vacancyRate = parseFloat(document.getElementById('vacancyRate').value) || 0;
var mgmtFee = parseFloat(document.getElementById('mgmtFee').value) || 0;
var maintenanceRate = parseFloat(document.getElementById('maintenance').value) || 0;
// Calculations
var downPaymentAmount = purchasePrice * (downPaymentPercent / 100);
var loanAmount = purchasePrice – downPaymentAmount;
var totalCashInvested = downPaymentAmount + closingCosts;
// Mortgage Calculation
var monthlyRate = (interestRate / 100) / 12;
var numberOfPayments = loanTerm * 12;
var monthlyMortgage = 0;
if (interestRate > 0) {
monthlyMortgage = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, numberOfPayments)) / (Math.pow(1 + monthlyRate, numberOfPayments) – 1);
} else {
monthlyMortgage = loanAmount / numberOfPayments;
}
// Monthly Expenses
var monthlyTax = annualTax / 12;
var monthlyInsurance = annualInsurance / 12;
var vacancyCost = monthlyRent * (vacancyRate / 100);
var mgmtCost = monthlyRent * (mgmtFee / 100);
var maintenanceCost = monthlyRent * (maintenanceRate / 100);
var totalOperatingExpenses = monthlyTax + monthlyInsurance + vacancyCost + mgmtCost + maintenanceCost;
var totalExpenses = totalOperatingExpenses + monthlyMortgage;
// ROI Metrics
var monthlyCashFlow = monthlyRent – totalExpenses;
var annualCashFlow = monthlyCashFlow * 12;
var monthlyNOI = monthlyRent – totalOperatingExpenses;
var annualNOI = monthlyNOI * 12;
var capRate = (purchasePrice > 0) ? (annualNOI / purchasePrice) * 100 : 0;
var cashOnCash = (totalCashInvested > 0) ? (annualCashFlow / totalCashInvested) * 100 : 0;
// Display Results
document.getElementById('results').style.display = 'block';
document.getElementById('resMortgage').innerText = formatCurrency(monthlyMortgage);
document.getElementById('resExpenses').innerText = formatCurrency(totalExpenses);
document.getElementById('resNOI').innerText = formatCurrency(monthlyNOI);
var cashFlowEl = document.getElementById('resCashFlow');
cashFlowEl.innerText = formatCurrency(monthlyCashFlow);
if (monthlyCashFlow < 0) {
cashFlowEl.classList.add('roi-neg');
cashFlowEl.classList.remove('roi-highlight');
} else {
cashFlowEl.classList.remove('roi-neg');
cashFlowEl.classList.add('roi-highlight');
}
document.getElementById('resCoC').innerText = cashOnCash.toFixed(2) + "%";
document.getElementById('resCapRate').innerText = capRate.toFixed(2) + "%";
}
function formatCurrency(num) {
return '$' + num.toFixed(2).replace(/\d(?=(\d{3})+\.)/g, '$&,');
}
Understanding Rental Property Cash Flow
Investing in real estate is one of the most reliable ways to build wealth, but simply buying a property doesn't guarantee a profit. Successful real estate investors rely on accurate data and calculations to determine if a property is a "deal" or a financial drain. This Rental Property Cash Flow Calculator is designed to help you analyze the profitability of a potential investment by looking at the most critical metrics: Cash Flow, Cap Rate, and Cash-on-Cash Return.
What is Cash Flow?
Cash flow is the net amount of cash moving into or out of your investment business. In the context of rental properties, it is calculated as:
- Gross Income (Rent) minus Total Expenses (Mortgage, Taxes, Insurance, Maintenance, Vacancy).
Positive cash flow means the property pays for itself and generates profit every month. Negative cash flow means you are paying out of pocket to hold the property, which is generally sustainable only if you are banking on significant appreciation.
Key Metrics Explained
1. Net Operating Income (NOI)
NOI is a calculation used to analyze the profitability of income-generating real estate investments. It equals all revenue from the property, minus all necessary operating expenses. critically, NOI excludes debt service (your mortgage payment). This allows you to judge the profitability of the property itself, regardless of financing.
2. Cap Rate (Capitalization Rate)
The Cap Rate is the ratio of Net Operating Income (NOI) to the property asset value (Purchase Price). It helps you compare the return of different properties on an apples-to-apples basis, assuming an all-cash purchase. A higher Cap Rate generally indicates a higher potential return, but may also come with higher risk.
Formula: Cap Rate = Annual NOI / Purchase Price
3. Cash-on-Cash Return (CoC)
This is arguably the most important metric for leveraged investors. It measures the annual return you made on the actual cash you invested (Down Payment + Closing Costs). Unlike the Cap Rate, CoC takes debt service into account.
Formula: CoC = Annual Pre-Tax Cash Flow / Total Cash Invested
Estimating Expenses Accurately
The biggest mistake new investors make is underestimating expenses. When using this calculator, ensure you account for:
- Vacancy: Properties are rarely occupied 100% of the time. A standard conservative estimate is 5-8% (about 2-3 weeks a year).
- Maintenance & CapEx: Even if the house is new, things break. Setting aside 5-10% of monthly rent ensures you have funds for repairs (leaky faucets) and Capital Expenditures (new roof, HVAC).
- Management Fees: Even if you plan to self-manage, you should account for your time or the potential future cost of a property manager (typically 8-12% of collected rent).
How to Interpret the Results
If your Cash Flow is positive, the property pays you to own it. If the Cash-on-Cash Return is higher than what you could earn in the stock market (e.g., 8-10%), it is likely a solid investment. However, always consider local market conditions, appreciation potential, and tax benefits which this calculator does not explicitly include.