.rental-calculator-container {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
max-width: 800px;
margin: 0 auto;
padding: 20px;
background: #fff;
color: #333;
}
.calc-box {
background: #f8f9fa;
padding: 30px;
border-radius: 8px;
box-shadow: 0 4px 15px rgba(0,0,0,0.05);
margin-bottom: 40px;
border: 1px solid #e9ecef;
}
.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;
font-size: 0.9rem;
color: #495057;
}
.input-group input {
width: 100%;
padding: 10px;
border: 1px solid #ced4da;
border-radius: 4px;
font-size: 1rem;
box-sizing: border-box;
}
.input-group input:focus {
border-color: #2271b1;
outline: none;
box-shadow: 0 0 0 2px rgba(34, 113, 177, 0.2);
}
.section-title {
grid-column: 1 / -1;
font-size: 1.1rem;
color: #2271b1;
border-bottom: 2px solid #e9ecef;
padding-bottom: 10px;
margin: 20px 0 15px 0;
font-weight: bold;
}
.section-title:first-child {
margin-top: 0;
}
.calc-btn {
grid-column: 1 / -1;
background: #2271b1;
color: white;
border: none;
padding: 15px;
font-size: 1.1rem;
font-weight: bold;
border-radius: 4px;
cursor: pointer;
transition: background 0.2s;
margin-top: 10px;
}
.calc-btn:hover {
background: #135e96;
}
.results-section {
display: none;
grid-column: 1 / -1;
background: #fff;
padding: 20px;
border-radius: 6px;
border-left: 5px solid #2271b1;
margin-top: 20px;
box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}
.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;
margin-bottom: 0;
padding-bottom: 0;
}
.result-label {
color: #666;
}
.result-value {
font-weight: bold;
font-size: 1.1rem;
}
.positive { color: #28a745; }
.negative { color: #dc3545; }
.article-content h2 {
color: #2c3338;
font-size: 1.8rem;
margin-top: 40px;
}
.article-content h3 {
color: #2c3338;
font-size: 1.4rem;
margin-top: 25px;
}
.article-content p, .article-content li {
line-height: 1.6;
color: #444;
font-size: 1.05rem;
margin-bottom: 15px;
}
.article-content ul {
padding-left: 20px;
}
function calculateRentalROI() {
// Get inputs
var purchasePrice = parseFloat(document.getElementById('purchasePrice').value) || 0;
var downPayment = 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 propertyTax = parseFloat(document.getElementById('propertyTax').value) || 0;
var insurance = parseFloat(document.getElementById('insurance').value) || 0;
var hoa = parseFloat(document.getElementById('hoa').value) || 0;
var maintenance = parseFloat(document.getElementById('maintenance').value) || 0;
var vacancyRate = parseFloat(document.getElementById('vacancy').value) || 0;
// Calculate Mortgage (Principal and Interest)
var loanAmount = purchasePrice – downPayment;
var monthlyRate = (interestRate / 100) / 12;
var numberOfPayments = loanTerm * 12;
var monthlyMortgage = 0;
if (interestRate > 0 && loanTerm > 0) {
monthlyMortgage = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, numberOfPayments)) / (Math.pow(1 + monthlyRate, numberOfPayments) – 1);
} else if (loanTerm > 0) {
monthlyMortgage = loanAmount / numberOfPayments;
}
// Calculate Vacancy Loss
var vacancyLoss = monthlyRent * (vacancyRate / 100);
// Total Monthly Operating Expenses (Excluding Mortgage)
var operatingExpenses = propertyTax + insurance + hoa + maintenance + vacancyLoss;
// Net Operating Income (NOI)
var noiMonthly = monthlyRent – operatingExpenses;
var noiAnnual = noiMonthly * 12;
// Total Monthly Expenses (Including Mortgage)
var totalMonthlyExpenses = operatingExpenses + monthlyMortgage;
// Monthly Cash Flow
var cashFlow = monthlyRent – totalMonthlyExpenses;
var annualCashFlow = cashFlow * 12;
// Cap Rate = (Annual NOI / Purchase Price) * 100
var capRate = 0;
if (purchasePrice > 0) {
capRate = (noiAnnual / purchasePrice) * 100;
}
// Cash on Cash Return = (Annual Cash Flow / Total Cash Invested) * 100
var totalCashInvested = downPayment + closingCosts;
var cocReturn = 0;
if (totalCashInvested > 0) {
cocReturn = (annualCashFlow / totalCashInvested) * 100;
}
// Display Results
document.getElementById('results').style.display = 'block';
document.getElementById('resMortgage').innerText = "$" + monthlyMortgage.toFixed(2);
document.getElementById('resExpenses').innerText = "$" + totalMonthlyExpenses.toFixed(2);
document.getElementById('resNOI').innerText = "$" + noiMonthly.toFixed(2);
var cfElement = document.getElementById('resCashFlow');
cfElement.innerText = "$" + cashFlow.toFixed(2);
cfElement.className = cashFlow >= 0 ? "result-value positive" : "result-value negative";
document.getElementById('resCapRate').innerText = capRate.toFixed(2) + "%";
var cocElement = document.getElementById('resCoC');
cocElement.innerText = cocReturn.toFixed(2) + "%";
cocElement.className = cocReturn >= 0 ? "result-value positive" : "result-value negative";
}
Property Purchase Details
Income & Expenses (Monthly)
Monthly Mortgage (P&I):
Total Monthly Expenses:
Net Operating Income (Monthly):
Monthly Cash Flow:
Cap Rate:
Cash on Cash Return:
Understanding Rental Property Cash Flow Analysis
Investing in real estate is one of the most reliable ways to build wealth, but success hinges on the numbers. The Rental Property Cash Flow Calculator above is designed to give investors a clear picture of a property's potential profitability before they sign on the dotted line. By inputting specific financial details, you can determine if a rental unit will generate passive income or become a financial burden.
Why Cash Flow is King
Cash flow is the net amount of money moving in and out of a real estate investment. Positive cash flow means the property generates more income than it costs to operate, providing you with monthly profit. This calculator breaks down your gross rental income against all potential liabilities, including mortgage payments, taxes, insurance, and often-overlooked costs like vacancy rates and maintenance reserves.
Key Metrics Explained
When analyzing a rental deal, two metrics stand out: Cap Rate and Cash on Cash Return.
- Net Operating Income (NOI): This is your total revenue minus all necessary operating expenses. Note that NOI calculates profitability before mortgage payments are considered, making it a pure measure of the property's efficiency.
- Cap Rate (Capitalization Rate): Calculated by dividing the NOI by the property's purchase price. It represents the potential return on investment if you paid all cash. A higher cap rate generally indicates a better return, though often with higher risk.
- Cash on Cash Return: This metric is crucial for investors using leverage (mortgages). It measures the annual pre-tax cash flow divided by the actual cash invested (down payment + closing costs). It tells you exactly how hard your invested dollars are working for you.
How to Estimate Expenses Accuratey
One of the biggest mistakes new investors make is underestimating expenses. Always account for Vacancy Rates (typically 5-10% depending on the market) to cover periods between tenants. Similarly, setting aside funds for Maintenance and Repairs is vital; a broken water heater or leaky roof can quickly wipe out a year's worth of profit if not budgeted for monthly.
Use this calculator to run multiple scenarios. What happens if the interest rate rises by 1%? What if you raise the rent by $100? Adjusting these variables will help you identify the "break-even" point and ensure your investment aligns with your financial goals.