#rental-property-calculator-container {
font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
max-width: 800px;
margin: 0 auto;
background: #ffffff;
border: 1px solid #e0e0e0;
border-radius: 8px;
padding: 25px;
box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}
#rental-property-calculator-container h2 {
text-align: center;
color: #2c3e50;
margin-bottom: 25px;
}
.calc-grid {
display: flex;
flex-wrap: wrap;
gap: 20px;
}
.calc-col {
flex: 1;
min-width: 250px;
}
.input-group {
margin-bottom: 15px;
}
.input-group label {
display: block;
margin-bottom: 5px;
color: #555;
font-weight: 600;
font-size: 0.9rem;
}
.input-group input, .input-group select {
width: 100%;
padding: 10px;
border: 1px solid #ddd;
border-radius: 4px;
font-size: 1rem;
box-sizing: border-box;
}
.input-group input:focus {
border-color: #3498db;
outline: none;
}
.section-title {
font-size: 1.1rem;
color: #3498db;
border-bottom: 2px solid #3498db;
padding-bottom: 5px;
margin-bottom: 15px;
margin-top: 10px;
}
button#calc-btn {
width: 100%;
padding: 15px;
background-color: #27ae60;
color: white;
border: none;
border-radius: 5px;
font-size: 1.1rem;
font-weight: bold;
cursor: pointer;
margin-top: 20px;
transition: background 0.3s;
}
button#calc-btn:hover {
background-color: #219150;
}
#results-area {
background-color: #f8f9fa;
padding: 20px;
border-radius: 8px;
margin-top: 25px;
display: none;
border: 1px solid #e9ecef;
}
.result-row {
display: flex;
justify-content: space-between;
padding: 10px 0;
border-bottom: 1px solid #e0e0e0;
}
.result-row:last-child {
border-bottom: none;
}
.result-label {
color: #555;
font-weight: 500;
}
.result-value {
font-weight: 800;
color: #2c3e50;
}
.positive { color: #27ae60; }
.negative { color: #c0392b; }
.main-metric {
font-size: 1.2rem;
padding: 15px 0;
background: #fff;
margin: 10px 0;
text-align: center;
border-radius: 5px;
border: 1px solid #ddd;
}
.calculator-content {
margin-top: 40px;
line-height: 1.6;
color: #333;
}
.calculator-content h3 {
color: #2c3e50;
margin-top: 20px;
}
.calculator-content ul {
padding-left: 20px;
}
.calculator-content li {
margin-bottom: 10px;
}
@media (max-width: 600px) {
.calc-col { min-width: 100%; }
}
function calculateRental() {
// Get Inputs
var price = parseFloat(document.getElementById('purchasePrice').value) || 0;
var downPayment = parseFloat(document.getElementById('downPayment').value) || 0;
var interestRate = parseFloat(document.getElementById('interestRate').value) || 0;
var termYears = parseFloat(document.getElementById('loanTerm').value) || 30;
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 monthlyHOA = parseFloat(document.getElementById('hoa').value) || 0;
var vacancyRate = parseFloat(document.getElementById('vacancyRate').value) || 0;
var maintenanceRate = parseFloat(document.getElementById('maintenanceRate').value) || 0;
// Calculations
// 1. Mortgage Payment (Principal & Interest)
var loanAmount = price – downPayment;
var monthlyRate = (interestRate / 100) / 12;
var numPayments = termYears * 12;
var monthlyMortgage = 0;
if (loanAmount > 0 && interestRate > 0) {
monthlyMortgage = (loanAmount * monthlyRate * Math.pow(1 + monthlyRate, numPayments)) / (Math.pow(1 + monthlyRate, numPayments) – 1);
} else if (loanAmount > 0 && interestRate === 0) {
monthlyMortgage = loanAmount / numPayments;
}
// 2. Monthly Operating Expenses
var monthlyTax = annualTax / 12;
var monthlyInsurance = annualInsurance / 12;
var monthlyVacancy = monthlyRent * (vacancyRate / 100);
var monthlyMaintenance = monthlyRent * (maintenanceRate / 100);
var totalOperatingExpenses = monthlyTax + monthlyInsurance + monthlyHOA + monthlyVacancy + monthlyMaintenance;
var totalMonthlyExpenses = totalOperatingExpenses + monthlyMortgage;
// 3. Cash Flow
var monthlyCashFlow = monthlyRent – totalMonthlyExpenses;
var annualCashFlow = monthlyCashFlow * 12;
// 4. NOI (Net Operating Income) – Income minus operating expenses (no mortgage)
var monthlyNOI = monthlyRent – totalOperatingExpenses;
var annualNOI = monthlyNOI * 12;
// 5. Cash Invested
var totalInvested = downPayment + closingCosts;
// 6. Metrics
var cashOnCash = 0;
if (totalInvested > 0) {
cashOnCash = (annualCashFlow / totalInvested) * 100;
}
var capRate = 0;
if (price > 0) {
capRate = (annualNOI / price) * 100;
}
// Formatting Function
var currencyFmt = new Intl.NumberFormat('en-US', { style: 'currency', currency: 'USD' });
var percentFmt = new Intl.NumberFormat('en-US', { minimumFractionDigits: 2, maximumFractionDigits: 2 });
// Display Results
document.getElementById('monthlyCashFlowDisplay').innerHTML = currencyFmt.format(monthlyCashFlow);
document.getElementById('monthlyCashFlowDisplay').className = monthlyCashFlow >= 0 ? "result-value positive" : "result-value negative";
document.getElementById('noiDisplay').innerHTML = currencyFmt.format(annualNOI);
document.getElementById('cocDisplay').innerHTML = percentFmt.format(cashOnCash) + "%";
document.getElementById('cocDisplay').className = cashOnCash >= 0 ? "result-value positive" : "result-value negative";
document.getElementById('capRateDisplay').innerHTML = percentFmt.format(capRate) + "%";
document.getElementById('totalInvestedDisplay').innerHTML = currencyFmt.format(totalInvested);
document.getElementById('mortgageDisplay').innerHTML = currencyFmt.format(monthlyMortgage);
document.getElementById('totalExpensesDisplay').innerHTML = currencyFmt.format(totalMonthlyExpenses);
// Show results area
document.getElementById('results-area').style.display = 'block';
}
Rental Property Cash Flow Calculator
Purchase & Loan
30 Years
20 Years
15 Years
10 Years
Income & Expenses
Monthly Cash Flow
$0.00
Net Operating Income (NOI) / Yr
$0.00
Cash on Cash ROI
0.00%
Cap Rate
0.00%
Total Cash Invested
$0.00
Monthly Mortgage (P&I)
$0.00
Total Monthly Expenses
$0.00
How to Analyze a Rental Property
Investing in real estate requires precise calculations to ensure a property will be profitable. This Rental Property Cash Flow Calculator helps investors evaluate the potential return on investment (ROI) by accounting for income, operating expenses, and debt service.
Understanding the Key Metrics
- Cash Flow: This is the net profit you pocket every month after paying the mortgage and all operating expenses. Positive cash flow ensures the property pays for itself.
- Net Operating Income (NOI): The total income minus operating expenses (excluding mortgage payments). This figure is crucial for calculating Cap Rate.
- Cap Rate (Capitalization Rate): Calculated as NOI / Purchase Price. It represents the rate of return on the property if you bought it all cash. It allows you to compare different properties regardless of financing.
- Cash on Cash ROI: Calculated as Annual Cash Flow / Total Cash Invested. This tells you how hard your actual invested money (down payment + closing costs) is working for you.
Typical Expense Guidelines
When estimating expenses, it is safer to be conservative. A common rule of thumb for Vacancy is 5-8% of rent, ensuring you have a buffer for turnover periods. For Maintenance and CapEx (Capital Expenditures like a new roof or HVAC), setting aside 10-15% of monthly rent is recommended to avoid surprise costs destroying your returns.