:root {
–primary-color: #2c3e50;
–accent-color: #27ae60;
–bg-color: #f8f9fa;
–text-color: #333;
–border-radius: 8px;
}
body {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
line-height: 1.6;
color: var(–text-color);
max-width: 800px;
margin: 0 auto;
padding: 20px;
background-color: #fff;
}
.calculator-container {
background-color: var(–bg-color);
padding: 30px;
border-radius: var(–border-radius);
box-shadow: 0 4px 6px rgba(0,0,0,0.1);
margin-bottom: 40px;
}
.calc-header {
text-align: center;
margin-bottom: 25px;
}
.calc-header h2 {
color: var(–primary-color);
margin: 0 0 10px 0;
}
.input-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
}
@media (max-width: 600px) {
.input-grid {
grid-template-columns: 1fr;
}
}
.input-group {
margin-bottom: 15px;
}
.input-group label {
display: block;
margin-bottom: 5px;
font-weight: 600;
font-size: 0.9em;
color: var(–primary-color);
}
.input-group input {
width: 100%;
padding: 10px;
border: 1px solid #ddd;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
.input-group input:focus {
border-color: var(–accent-color);
outline: none;
}
.section-title {
grid-column: 1 / -1;
font-size: 1.1em;
font-weight: bold;
color: var(–primary-color);
border-bottom: 2px solid #ddd;
padding-bottom: 5px;
margin-top: 10px;
margin-bottom: 15px;
}
.btn-calc {
grid-column: 1 / -1;
background-color: var(–accent-color);
color: white;
border: none;
padding: 15px;
font-size: 1.1em;
font-weight: bold;
border-radius: 4px;
cursor: pointer;
transition: background-color 0.2s;
margin-top: 10px;
width: 100%;
}
.btn-calc:hover {
background-color: #219150;
}
#results-area {
margin-top: 30px;
padding: 20px;
background-color: white;
border-radius: var(–border-radius);
border-left: 5px solid var(–accent-color);
display: none;
}
.result-row {
display: flex;
justify-content: space-between;
margin-bottom: 10px;
padding-bottom: 10px;
border-bottom: 1px solid #eee;
}
.result-row:last-child {
border-bottom: none;
}
.result-label {
font-weight: 500;
}
.result-value {
font-weight: bold;
color: var(–primary-color);
}
.highlight-result {
color: var(–accent-color);
font-size: 1.2em;
}
.article-content {
margin-top: 50px;
}
.article-content h2 {
color: var(–primary-color);
margin-top: 30px;
}
.article-content p {
margin-bottom: 15px;
}
.article-content ul {
margin-bottom: 15px;
}
.error-msg {
color: #e74c3c;
text-align: center;
margin-top: 10px;
display: none;
}
Understanding Rental Property Metrics
Investing in real estate requires more than just finding a tenant; it requires a deep understanding of the financial metrics that determine whether a property is a good deal. Our Rental Property Calculator is designed to help investors analyze the profitability of a potential real estate investment by computing key indicators like Cap Rate, Cash Flow, and Cash on Cash Return.
Key Metrics Explained
1. Net Operating Income (NOI)
NOI is one of the most important figures in real estate. It represents the total income the property generates after all operating expenses are paid, but before mortgage payments. Calculating NOI helps you compare properties without the influence of financing structures.
Formula: NOI = (Gross Rental Income – Vacancy Losses) – Operating Expenses
2. Capitalization Rate (Cap Rate)
The Cap Rate indicates the rate of return on a real estate investment property based on the income that the property is expected to generate. It is useful for comparing the profitability of different properties independent of how they are financed. A higher Cap Rate generally implies a higher potential return, though often with higher risk.
Example: If you buy a property for $250,000 and it generates $15,000 in NOI, the Cap Rate is ($15,000 / $250,000) = 6%.
3. Cash Flow
Cash Flow is the net amount of cash moving in and out of the investment. Positive cash flow means the property is generating income for you every month after the mortgage and all expenses are paid. For buy-and-hold investors, positive monthly cash flow is often the primary goal.
4. Cash on Cash Return
This metric measures the annual return on the actual cash you invested (down payment + closing costs), rather than the total purchase price. It gives you a realistic view of how hard your money is working for you.
How to Use This Calculator
To get an accurate analysis, gather the following data points:
- Purchase Price & Financing: The cost of the home and your loan details.
- Rental Income: Conservative estimates of monthly rent.
- Vacancy Rate: The percentage of time the property sits empty (typically 5-10%).
- Expenses: Taxes, insurance, HOA fees, maintenance reserves, and property management fees.
By inputting conservative numbers, you can stress-test your investment to ensure it remains profitable even if expenses rise or rent prices stagnate.
function calculateRentalMetrics() {
// Clear previous error
document.getElementById('error-message').style.display = 'none';
document.getElementById('results-area').style.display = 'none';
// 1. Get Inputs
var purchasePrice = parseFloat(document.getElementById('purchasePrice').value);
var closingCosts = parseFloat(document.getElementById('closingCosts').value) || 0;
var downPayment = parseFloat(document.getElementById('downPayment').value);
var interestRate = parseFloat(document.getElementById('interestRate').value);
var loanTerm = parseFloat(document.getElementById('loanTerm').value);
var monthlyRent = parseFloat(document.getElementById('monthlyRent').value);
var vacancyRate = parseFloat(document.getElementById('vacancyRate').value) || 0;
var propertyTax = parseFloat(document.getElementById('propertyTax').value) || 0;
var insurance = parseFloat(document.getElementById('insurance').value) || 0;
var maintenance = parseFloat(document.getElementById('maintenance').value) || 0;
var mgmtFeePercent = parseFloat(document.getElementById('mgmtFee').value) || 0;
// Validation
if (isNaN(purchasePrice) || isNaN(downPayment) || isNaN(monthlyRent)) {
document.getElementById('error-message').style.display = 'block';
return;
}
// 2. Calculate Mortgage Payment
var loanAmount = purchasePrice – downPayment;
var monthlyRate = (interestRate / 100) / 12;
var totalPayments = loanTerm * 12;
var monthlyPI = 0;
if (interestRate > 0) {
monthlyPI = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, totalPayments)) / (Math.pow(1 + monthlyRate, totalPayments) – 1);
} else {
monthlyPI = loanAmount / totalPayments;
}
// 3. Income Calculations
var grossAnnualRent = monthlyRent * 12;
var vacancyLoss = grossAnnualRent * (vacancyRate / 100);
var effectiveGrossIncome = grossAnnualRent – vacancyLoss;
// 4. Expense Calculations
var annualMgmtFee = effectiveGrossIncome * (mgmtFeePercent / 100);
var totalAnnualOperatingExpenses = propertyTax + insurance + maintenance + annualMgmtFee;
// 5. Metric Calculations
// NOI
var annualNOI = effectiveGrossIncome – totalAnnualOperatingExpenses;
// Annual Debt Service
var annualDebtService = monthlyPI * 12;
// Cash Flow
var annualCashFlow = annualNOI – annualDebtService;
var monthlyCashFlow = annualCashFlow / 12;
// Cap Rate
var capRate = (annualNOI / purchasePrice) * 100;
// Cash on Cash Return
var totalCashInvested = downPayment + closingCosts;
var cashOnCash = 0;
if (totalCashInvested > 0) {
cashOnCash = (annualCashFlow / totalCashInvested) * 100;
}
// 6. Formatting Helper
function formatMoney(num) {
return '$' + num.toFixed(2).replace(/\d(?=(\d{3})+\.)/g, '$&,');
}
// 7. Update UI
document.getElementById('res-noi').innerText = formatMoney(annualNOI);
document.getElementById('res-cashflow').innerText = formatMoney(monthlyCashFlow);
document.getElementById('res-caprate').innerText = capRate.toFixed(2) + "%";
document.getElementById('res-coc').innerText = cashOnCash.toFixed(2) + "%";
document.getElementById('res-cashneeded').innerText = formatMoney(totalCashInvested);
// Show results
document.getElementById('results-area').style.display = 'block';
}