.calculator-container {
max-width: 800px;
margin: 0 auto;
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
background: #fff;
padding: 20px;
border-radius: 8px;
box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}
.calc-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
}
@media (max-width: 600px) {
.calc-grid {
grid-template-columns: 1fr;
}
}
.input-group {
margin-bottom: 15px;
}
.input-group label {
display: block;
margin-bottom: 5px;
font-weight: 600;
color: #333;
}
.input-group input {
width: 100%;
padding: 10px;
border: 1px solid #ddd;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
.calc-btn {
background-color: #0073aa;
color: white;
border: none;
padding: 15px 30px;
font-size: 18px;
border-radius: 4px;
cursor: pointer;
width: 100%;
margin-top: 20px;
font-weight: bold;
transition: background 0.3s;
}
.calc-btn:hover {
background-color: #005177;
}
.results-box {
background-color: #f8f9fa;
border: 1px solid #e9ecef;
border-radius: 4px;
padding: 20px;
margin-top: 30px;
display: none;
}
.result-row {
display: flex;
justify-content: space-between;
padding: 10px 0;
border-bottom: 1px solid #ddd;
}
.result-row:last-child {
border-bottom: none;
}
.result-label {
font-weight: 600;
color: #555;
}
.result-value {
font-weight: bold;
color: #2c3e50;
}
.highlight-result {
color: #27ae60;
font-size: 1.2em;
}
.article-content {
margin-top: 50px;
line-height: 1.6;
color: #333;
}
.article-content h2 {
color: #2c3e50;
border-bottom: 2px solid #0073aa;
padding-bottom: 10px;
margin-top: 30px;
}
.article-content h3 {
color: #444;
margin-top: 20px;
}
.article-content ul {
padding-left: 20px;
}
.article-content li {
margin-bottom: 10px;
}
.error-msg {
color: #d63031;
margin-top: 10px;
display: none;
text-align: center;
}
Please enter valid numeric values for all fields.
function calculateRentalROI() {
// Get Input Values
var price = parseFloat(document.getElementById('rp_purchase_price').value);
var downPayment = parseFloat(document.getElementById('rp_down_payment').value);
var closingCosts = parseFloat(document.getElementById('rp_closing_costs').value);
var interestRate = parseFloat(document.getElementById('rp_interest_rate').value);
var termYears = parseFloat(document.getElementById('rp_loan_term').value);
var rent = parseFloat(document.getElementById('rp_rental_income').value);
var tax = parseFloat(document.getElementById('rp_property_tax').value);
var insurance = parseFloat(document.getElementById('rp_insurance').value);
var hoa = parseFloat(document.getElementById('rp_hoa').value);
var maintenance = parseFloat(document.getElementById('rp_maintenance').value);
var errorDiv = document.getElementById('rp_error');
var resultsDiv = document.getElementById('rp_results');
// Validation
if (isNaN(price) || isNaN(downPayment) || isNaN(interestRate) || isNaN(termYears) ||
isNaN(rent) || isNaN(tax) || isNaN(insurance) || isNaN(hoa) || isNaN(maintenance)) {
errorDiv.style.display = 'block';
resultsDiv.style.display = 'none';
return;
}
errorDiv.style.display = 'none';
// Mortgage Calculation
var loanAmount = price – downPayment;
var monthlyRate = (interestRate / 100) / 12;
var numPayments = termYears * 12;
var mortgagePayment = 0;
if (monthlyRate > 0) {
mortgagePayment = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, numPayments)) / (Math.pow(1 + monthlyRate, numPayments) – 1);
} else {
mortgagePayment = loanAmount / numPayments;
}
// Expense Calculation
var totalMonthlyExpenses = tax + insurance + hoa + maintenance;
var totalAnnualOperatingExpenses = totalMonthlyExpenses * 12;
// Income Calculation
var annualGrossIncome = rent * 12;
// NOI Calculation (Income – Operating Expenses, before debt service)
var noi = annualGrossIncome – totalAnnualOperatingExpenses;
// Cash Flow Calculation
var monthlyCashFlow = rent – totalMonthlyExpenses – mortgagePayment;
var annualCashFlow = monthlyCashFlow * 12;
// Investment Calculation
var totalCashInvested = downPayment + closingCosts;
if (isNaN(closingCosts)) {
totalCashInvested = downPayment;
}
// ROI Metrics
var capRate = (noi / price) * 100;
var cocReturn = (annualCashFlow / totalCashInvested) * 100;
// Formatting Helper
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
minimumFractionDigits: 2
});
// Display Results
document.getElementById('res_noi').innerHTML = formatter.format(noi);
document.getElementById('res_mortgage').innerHTML = formatter.format(mortgagePayment);
document.getElementById('res_monthly_cf').innerHTML = formatter.format(monthlyCashFlow);
document.getElementById('res_annual_cf').innerHTML = formatter.format(annualCashFlow);
document.getElementById('res_cash_invested').innerHTML = formatter.format(totalCashInvested);
document.getElementById('res_cap_rate').innerHTML = capRate.toFixed(2) + "%";
document.getElementById('res_coc').innerHTML = cocReturn.toFixed(2) + "%";
// Color coding for negative flow
if (monthlyCashFlow < 0) {
document.getElementById('res_monthly_cf').style.color = '#e74c3c';
} else {
document.getElementById('res_monthly_cf').style.color = '#27ae60';
}
resultsDiv.style.display = 'block';
}
Understanding Rental Property ROI
Investing in real estate is a powerful way to build wealth, but not every property is a good deal. To maximize your returns, you must perform a thorough financial analysis before signing any contracts. This Rental Property ROI Calculator is designed to help investors determine two critical metrics: Cash Flow and Cash on Cash Return.
What is Cash on Cash Return?
Cash on Cash (CoC) Return is a rate of return ratio that calculates the annual cash income earned on the cash you actually invested. Unlike a standard Return on Investment (ROI) calculation which might look at the total value of the asset, CoC specifically measures the efficiency of the cash you deployed.
The formula is:
Cash on Cash Return = (Annual Pre-Tax Cash Flow / Total Cash Invested) × 100
If you put $50,000 down on a property and it generates $5,000 in positive cash flow per year, your CoC return is 10%. This is often a more useful metric than Cap Rate for investors utilizing leverage (mortgages).
Key Metrics Defined
- Net Operating Income (NOI): Your total rental income minus all operating expenses (taxes, insurance, maintenance, HOA) but excluding mortgage payments.
- Cap Rate: A measure of the property's natural rate of return assuming you bought it with all cash. It is calculated as NOI divided by Purchase Price.
- Cash Flow: The money left in your pocket each month after paying all operating expenses and the mortgage.
- Total Cash Invested: The sum of your down payment, closing costs, and any immediate repair costs needed to get the property rent-ready.
Example Scenario
Let's look at a realistic example to see how the numbers work:
- Purchase Price: $300,000
- Down Payment: $60,000 (20%)
- Monthly Rent: $2,500
- Mortgage Payment: ~$1,500 (Principal & Interest)
- Operating Expenses: $600 (Taxes, Insurance, Repairs)
In this scenario, your total monthly outflow is $2,100 ($1,500 mortgage + $600 expenses). Your monthly cash flow is $400 ($2,500 Rent – $2,100 Outflow). This equals $4,800 per year. If you invested $65,000 total (including closing costs), your Cash on Cash return would be roughly 7.4%.
How to Use This Calculator
Simply enter the details of your potential investment property in the fields above. Be sure to estimate expenses conservatively; maintenance costs and vacancies are real factors that impact long-term profitability. Once you click "Calculate ROI," the tool will provide a breakdown of your projected financial performance, helping you decide if the property fits your investment goals.