.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: 20px;
box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}
.calc-header {
text-align: center;
margin-bottom: 30px;
border-bottom: 2px solid #2c3e50;
padding-bottom: 15px;
}
.calc-header h2 {
color: #2c3e50;
margin: 0;
font-size: 24px;
}
.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: #555;
font-size: 14px;
}
.input-group input, .input-group select {
width: 100%;
padding: 10px;
border: 1px solid #ddd;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
.input-group input:focus {
border-color: #3498db;
outline: none;
}
.calc-btn-wrapper {
grid-column: 1 / -1;
text-align: center;
margin-top: 10px;
}
.calc-btn {
background-color: #27ae60;
color: white;
border: none;
padding: 12px 30px;
font-size: 18px;
border-radius: 5px;
cursor: pointer;
transition: background 0.3s;
}
.calc-btn:hover {
background-color: #219150;
}
.results-section {
grid-column: 1 / -1;
background-color: #f8f9fa;
border: 1px solid #e9ecef;
border-radius: 6px;
padding: 20px;
margin-top: 20px;
display: none;
}
.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 {
font-weight: 600;
color: #444;
}
.result-value {
font-weight: 700;
color: #2c3e50;
}
.positive-flow {
color: #27ae60 !important;
}
.negative-flow {
color: #c0392b !important;
}
.article-content {
margin-top: 40px;
line-height: 1.6;
color: #333;
}
.article-content h3 {
color: #2c3e50;
margin-top: 25px;
}
.article-content p {
margin-bottom: 15px;
}
.article-content ul {
margin-bottom: 20px;
padding-left: 20px;
}
.help-text {
font-size: 12px;
color: #888;
margin-top: 2px;
}
function calculateCashFlow() {
// 1. Get Input Values
var price = parseFloat(document.getElementById("purchasePrice").value) || 0;
var downPayment = parseFloat(document.getElementById("downPayment").value) || 0;
var rent = parseFloat(document.getElementById("monthlyRent").value) || 0;
var interestRate = parseFloat(document.getElementById("interestRate").value) || 0;
var termYears = parseFloat(document.getElementById("loanTerm").value) || 30;
var annualTax = parseFloat(document.getElementById("propertyTax").value) || 0;
var annualInsurance = parseFloat(document.getElementById("insurance").value) || 0;
var vacancyRate = parseFloat(document.getElementById("vacancyRate").value) || 0;
var maintenanceRate = parseFloat(document.getElementById("maintenance").value) || 0;
var hoaFees = parseFloat(document.getElementById("hoaFees").value) || 0;
// 2. Calculate Mortgage
var loanAmount = price – downPayment;
var monthlyRate = (interestRate / 100) / 12;
var numberOfPayments = termYears * 12;
var monthlyMortgage = 0;
if (loanAmount > 0 && interestRate > 0) {
monthlyMortgage = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, numberOfPayments)) / (Math.pow(1 + monthlyRate, numberOfPayments) – 1);
} else if (loanAmount > 0 && interestRate === 0) {
monthlyMortgage = loanAmount / numberOfPayments;
}
// 3. Calculate Operating Expenses
var monthlyTax = annualTax / 12;
var monthlyInsurance = annualInsurance / 12;
var monthlyVacancy = rent * (vacancyRate / 100);
var monthlyMaintenance = rent * (maintenanceRate / 100);
var totalOperatingExpenses = monthlyTax + monthlyInsurance + monthlyVacancy + monthlyMaintenance + hoaFees;
var totalMonthlyExpenses = monthlyMortgage + totalOperatingExpenses;
// 4. Calculate Key Metrics
var netOperatingIncome = rent – totalOperatingExpenses; // NOI (Monthly)
var monthlyCashFlow = rent – totalMonthlyExpenses;
var annualCashFlow = monthlyCashFlow * 12;
// Cash on Cash Return = Annual Cash Flow / Total Cash Invested (assuming Down Payment is total investment for simplicity here)
var cashOnCash = 0;
if (downPayment > 0) {
cashOnCash = (annualCashFlow / downPayment) * 100;
}
// Cap Rate = (Annual NOI / Purchase Price)
var annualNOI = netOperatingIncome * 12;
var capRate = 0;
if (price > 0) {
capRate = (annualNOI / price) * 100;
}
// 5. Display Results
document.getElementById("dispMortgage").innerText = formatCurrency(monthlyMortgage);
document.getElementById("dispExpenses").innerText = formatCurrency(totalMonthlyExpenses);
document.getElementById("dispNOI").innerText = formatCurrency(netOperatingIncome);
var cfElement = document.getElementById("dispCashFlow");
cfElement.innerText = formatCurrency(monthlyCashFlow);
// Styling for positive/negative cash flow
if (monthlyCashFlow >= 0) {
cfElement.classList.remove("negative-flow");
cfElement.classList.add("positive-flow");
} else {
cfElement.classList.remove("positive-flow");
cfElement.classList.add("negative-flow");
}
document.getElementById("dispCoC").innerText = cashOnCash.toFixed(2) + "%";
document.getElementById("dispCapRate").innerText = capRate.toFixed(2) + "%";
// Show results container
document.getElementById("resultContainer").style.display = "block";
}
function formatCurrency(num) {
return "$" + num.toFixed(2).replace(/\d(?=(\d{3})+\.)/g, '$&,');
}
Rental Property Cash Flow Calculator
Initial cash invested
15 Years
30 Years
Est. time property sits empty
% of Monthly Rent set aside
Analysis Results
Monthly Mortgage Payment (P&I):
$0.00
Total Monthly Expenses:
$0.00
Net Operating Income (NOI) (Monthly):
$0.00
Estimated Monthly Cash Flow:
$0.00
Cash-on-Cash Return (Annual):
0.00%
Cap Rate:
0.00%
Understanding Rental Property Cash Flow
Analyzing a rental property investment requires more than just comparing the rent to the mortgage. A comprehensive cash flow analysis considers vacancy rates, maintenance reserves, and operating expenses to determine the true profitability of an asset.
Key Metrics Explained
- Monthly Cash Flow: The net amount of profit left in your pocket each month after all operating expenses and debt service (mortgage) are paid. Positive cash flow is essential for sustainable investing.
- Cash-on-Cash Return (CoC): This measures the annual return on the actual cash you invested (down payment + closing costs). It is a critical metric for comparing the efficiency of your capital against other investment vehicles like stocks or bonds.
- Cap Rate (Capitalization Rate): This metric evaluates the profitability of the property irrespective of how it is financed. It is calculated by dividing the Net Operating Income (NOI) by the property's purchase price.
- Vacancy & Maintenance: Savvy investors always allocate a percentage of rent (typically 5-10%) for vacancies and repairs. Ignoring these costs can lead to negative cash flow surprises.
How to Use This Calculator
Enter your purchase details, financing terms, and estimated expenses. Be realistic with your vacancy and maintenance estimates—older properties usually require higher maintenance percentages (10-15%), while newer homes might only need 5%.