.rental-calculator-wrapper {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
max-width: 800px;
margin: 0 auto;
padding: 20px;
background: #fff;
border-radius: 8px;
box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}
.rental-calc-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
margin-bottom: 25px;
}
@media (max-width: 600px) {
.rental-calc-grid {
grid-template-columns: 1fr;
}
}
.rental-input-group {
margin-bottom: 15px;
}
.rental-input-group label {
display: block;
margin-bottom: 5px;
font-weight: 600;
color: #333;
font-size: 14px;
}
.rental-input-group input {
width: 100%;
padding: 10px;
border: 1px solid #ddd;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
.rental-input-group input:focus {
border-color: #2c3e50;
outline: none;
}
.calc-btn {
background-color: #27ae60;
color: white;
border: none;
padding: 15px 30px;
font-size: 18px;
font-weight: bold;
border-radius: 4px;
cursor: pointer;
width: 100%;
transition: background 0.3s;
margin-bottom: 25px;
}
.calc-btn:hover {
background-color: #219150;
}
.results-section {
background-color: #f8f9fa;
padding: 20px;
border-radius: 6px;
border: 1px solid #e9ecef;
display: none;
}
.results-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
}
.result-item {
background: white;
padding: 15px;
border-radius: 4px;
border-left: 4px solid #27ae60;
box-shadow: 0 1px 3px rgba(0,0,0,0.05);
}
.result-item.negative {
border-left-color: #e74c3c;
}
.result-label {
font-size: 13px;
color: #666;
margin-bottom: 5px;
text-transform: uppercase;
letter-spacing: 0.5px;
}
.result-value {
font-size: 24px;
font-weight: 700;
color: #2c3e50;
}
.content-section {
margin-top: 40px;
line-height: 1.6;
color: #444;
}
.content-section h2 {
color: #2c3e50;
margin-top: 30px;
}
.content-section h3 {
color: #34495e;
margin-top: 20px;
}
.content-section ul {
padding-left: 20px;
}
.content-section li {
margin-bottom: 10px;
}
function calculateRentalCashFlow() {
// 1. Get Input Values
var price = parseFloat(document.getElementById('propPrice').value) || 0;
var downPct = parseFloat(document.getElementById('downPaymentPct').value) || 0;
var closingCosts = parseFloat(document.getElementById('closingCosts').value) || 0;
var rate = parseFloat(document.getElementById('intRate').value) || 0;
var termYears = parseFloat(document.getElementById('loanTerm').value) || 0;
var rent = parseFloat(document.getElementById('monthlyRent').value) || 0;
var annualTax = parseFloat(document.getElementById('annualTax').value) || 0;
var annualIns = parseFloat(document.getElementById('annualIns').value) || 0;
var monthlyHoa = parseFloat(document.getElementById('monthlyHoa').value) || 0;
var vacancyRate = parseFloat(document.getElementById('vacancyRate').value) || 0;
// 2. Calculate Loan Details
var downAmount = price * (downPct / 100);
var loanAmount = price – downAmount;
var totalCashInvested = downAmount + closingCosts;
// Monthly Mortgage Calculation
var monthlyRate = (rate / 100) / 12;
var numPayments = termYears * 12;
var monthlyMortgage = 0;
if (rate > 0 && termYears > 0) {
monthlyMortgage = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, numPayments)) / (Math.pow(1 + monthlyRate, numPayments) – 1);
} else if (termYears > 0) {
monthlyMortgage = loanAmount / numPayments;
}
// 3. Calculate Expenses
var monthlyTax = annualTax / 12;
var monthlyIns = annualIns / 12;
var monthlyVacancyCost = rent * (vacancyRate / 100);
var totalMonthlyExpenses = monthlyMortgage + monthlyTax + monthlyIns + monthlyHoa + monthlyVacancyCost;
// 4. Calculate Returns
var monthlyCashFlow = rent – totalMonthlyExpenses;
var annualCashFlow = monthlyCashFlow * 12;
// NOI (Net Operating Income) does NOT include mortgage (Principal & Interest)
// NOI = Income – Operating Expenses (Vacancy, Tax, Ins, HOA/Maint)
var monthlyOperatingExpenses = monthlyTax + monthlyIns + monthlyHoa + monthlyVacancyCost;
var annualNOI = (rent * 12) – (monthlyOperatingExpenses * 12);
var cocReturn = 0;
if (totalCashInvested > 0) {
cocReturn = (annualCashFlow / totalCashInvested) * 100;
}
var capRate = 0;
if (price > 0) {
capRate = (annualNOI / price) * 100;
}
// 5. Update UI
document.getElementById('resultsArea').style.display = 'block';
// Formatting currency
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
minimumFractionDigits: 2
});
document.getElementById('resMonthlyCashFlow').innerText = formatter.format(monthlyCashFlow);
document.getElementById('resTotalExpenses').innerText = formatter.format(totalMonthlyExpenses);
document.getElementById('resMortgage').innerText = formatter.format(monthlyMortgage);
document.getElementById('resTotalCash').innerText = formatter.format(totalCashInvested);
document.getElementById('resCocReturn').innerText = cocReturn.toFixed(2) + "%";
document.getElementById('resCapRate').innerText = capRate.toFixed(2) + "%";
// Color coding cash flow
var cfBox = document.getElementById('cf-box');
if (monthlyCashFlow < 0) {
cfBox.classList.add('negative');
document.getElementById('resMonthlyCashFlow').style.color = '#c0392b';
} else {
cfBox.classList.remove('negative');
document.getElementById('resMonthlyCashFlow').style.color = '#2c3e50';
}
}
Rental Property Cash Flow Calculator
Purchase & Loan Details
Income & Recurring Expenses
Investment Analysis
Monthly Cash Flow
$0.00
Cash on Cash Return
0.00%
Cap Rate
0.00%
Total Monthly Expenses
$0.00
Monthly Mortgage
$0.00
Total Cash Needed
$0.00
Understanding Your Rental Property Investment
Investing in real estate is a powerful way to build wealth, but the difference between a profitable asset and a financial liability often comes down to the numbers. This Rental Property Cash Flow Calculator is designed to help investors accurately analyze the potential returns of a real estate purchase.
Key Metrics Explained
1. Monthly Cash Flow
This is the net profit you pocket every month after all expenses are paid. It is calculated as:
Cash Flow = Total Rental Income – (Mortgage + Taxes + Insurance + HOA + Vacancy Reserves)
A positive cash flow ensures the property pays for itself and provides passive income.
2. Cash on Cash Return (CoC)
This metric measures the return on the actual cash you invested (down payment + closing costs), not the total property price. It tells you how hard your money is working for you.
Example: If you invest $50,000 cash to buy a property and it generates $5,000 in annual net cash flow, your Cash on Cash return is 10%.
3. Cap Rate (Capitalization Rate)
Cap Rate measures the property's natural rate of return assuming it was bought entirely with cash. It is useful for comparing the profitability of different properties regardless of financing.
Cap Rate = Net Operating Income (NOI) / Property Asset Value
How to Use This Calculator
- Purchase Price: The negotiated price of the property.
- Down Payment & Loan: Determines your leverage. A higher down payment reduces monthly mortgage costs but increases initial cash needed.
- Operating Expenses: Be realistic with taxes, insurance, and maintenance (HOA). Don't forget to account for vacancy rates (typically 5-10%) to account for months when the property is empty.
Use these insights to make data-driven investment decisions and maximize your real estate portfolio's profitability.