Rental Property Cash Flow & ROI Calculator
.roi-calc-wrapper {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
max-width: 800px;
margin: 0 auto;
border: 1px solid #e2e8f0;
border-radius: 8px;
background: #fff;
box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
overflow: hidden;
}
.roi-calc-header {
background: #2c3e50;
color: #fff;
padding: 20px;
text-align: center;
}
.roi-calc-header h2 {
margin: 0;
font-size: 24px;
}
.roi-calc-body {
padding: 25px;
display: flex;
flex-wrap: wrap;
gap: 30px;
}
.roi-input-section {
flex: 1;
min-width: 300px;
}
.roi-result-section {
flex: 1;
min-width: 300px;
background: #f8fafc;
padding: 20px;
border-radius: 8px;
border: 1px solid #cbd5e1;
}
.form-group {
margin-bottom: 15px;
}
.form-group label {
display: block;
font-weight: 600;
margin-bottom: 5px;
color: #374151;
font-size: 14px;
}
.form-group input {
width: 100%;
padding: 10px;
border: 1px solid #cbd5e1;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
.form-group .input-icon {
position: relative;
}
.form-group .input-icon span {
position: absolute;
left: 10px;
top: 50%;
transform: translateY(-50%);
color: #64748b;
}
.form-group .input-icon input {
padding-left: 25px;
}
.calc-btn {
width: 100%;
padding: 12px;
background: #27ae60;
color: white;
border: none;
border-radius: 4px;
font-size: 16px;
font-weight: bold;
cursor: pointer;
transition: background 0.2s;
margin-top: 10px;
}
.calc-btn:hover {
background: #219150;
}
.result-row {
display: flex;
justify-content: space-between;
align-items: center;
padding: 12px 0;
border-bottom: 1px solid #e2e8f0;
}
.result-row:last-child {
border-bottom: none;
}
.result-label {
font-size: 14px;
color: #64748b;
}
.result-value {
font-weight: 700;
font-size: 18px;
color: #1e293b;
}
.highlight-result {
color: #27ae60;
font-size: 22px;
}
.negative {
color: #ef4444;
}
.calc-article {
max-width: 800px;
margin: 40px auto;
line-height: 1.6;
color: #333;
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}
.calc-article h2 {
color: #2c3e50;
border-bottom: 2px solid #27ae60;
padding-bottom: 10px;
margin-top: 30px;
}
.calc-article h3 {
color: #2c3e50;
margin-top: 25px;
}
.calc-article ul {
margin-bottom: 20px;
}
.calc-article li {
margin-bottom: 8px;
}
@media (max-width: 600px) {
.roi-calc-body {
flex-direction: column;
}
}
Financial Analysis
Monthly Mortgage (P&I):
$0.00
Total Monthly Costs:
$0.00
Net Operating Income (Annual):
$0.00
Monthly Cash Flow:
$0.00
Cap Rate:
0.00%
Cash on Cash Return:
0.00%
function calculateROI() {
// 1. Get Input Values
var price = parseFloat(document.getElementById("propPrice").value);
var down = parseFloat(document.getElementById("downPayment").value);
var rate = parseFloat(document.getElementById("intRate").value);
var years = parseFloat(document.getElementById("loanTerm").value);
var rent = parseFloat(document.getElementById("monthlyRent").value);
var expenses = parseFloat(document.getElementById("monthlyExp").value);
// Validation
if (isNaN(price) || isNaN(down) || isNaN(rate) || isNaN(years) || isNaN(rent) || isNaN(expenses)) {
alert("Please enter valid numbers in all fields.");
return;
}
// 2. Calculate Mortgage (Principal & Interest)
var loanAmount = price – down;
var monthlyRate = (rate / 100) / 12;
var numPayments = years * 12;
var mortgagePayment = 0;
if (rate === 0) {
mortgagePayment = loanAmount / numPayments;
} else {
mortgagePayment = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, numPayments)) / (Math.pow(1 + monthlyRate, numPayments) – 1);
}
// 3. Calculate Financial Metrics
var totalMonthlyCost = mortgagePayment + expenses;
var monthlyCashFlow = rent – totalMonthlyCost;
var annualCashFlow = monthlyCashFlow * 12;
// Net Operating Income (NOI) = (Rent – Operating Expenses) * 12
// Note: Mortgage is not an operating expense for Cap Rate calculation
var annualNOI = (rent – expenses) * 12;
// Cap Rate = (NOI / Purchase Price) * 100
var capRate = (annualNOI / price) * 100;
// Cash on Cash Return = (Annual Pre-Tax Cash Flow / Total Cash Invested) * 100
// Assuming Total Cash Invested = Down Payment (simplified)
var cashOnCash = 0;
if (down > 0) {
cashOnCash = (annualCashFlow / down) * 100;
}
// 4. Update UI
// Helper for currency formatting
var fmtMoney = new Intl.NumberFormat('en-US', { style: 'currency', currency: 'USD' });
document.getElementById("resMortgage").innerText = fmtMoney.format(mortgagePayment);
document.getElementById("resTotalCost").innerText = fmtMoney.format(totalMonthlyCost);
document.getElementById("resNOI").innerText = fmtMoney.format(annualNOI);
var cfElem = document.getElementById("resCashFlow");
cfElem.innerText = fmtMoney.format(monthlyCashFlow);
// Styling for positive/negative cash flow
if(monthlyCashFlow < 0) {
cfElem.classList.add("negative");
cfElem.classList.remove("highlight-result");
} else {
cfElem.classList.remove("negative");
cfElem.classList.add("highlight-result");
}
document.getElementById("resCapRate").innerText = capRate.toFixed(2) + "%";
var cocElem = document.getElementById("resCoC");
cocElem.innerText = cashOnCash.toFixed(2) + "%";
if(cashOnCash < 0) cocElem.classList.add("negative");
else cocElem.classList.remove("negative");
}
// Run once on load to populate zeros correctly
window.onload = function() {
calculateROI();
};
Understanding Rental Property ROI Metrics
Investing in real estate is one of the most reliable ways to build wealth, but simply buying a property doesn't guarantee a profit. To succeed, investors must analyze the numbers rigorously. This Rental Property Cash Flow & ROI Calculator helps you evaluate the potential profitability of an investment by breaking down the most critical metrics: Cash Flow, Cap Rate, and Cash on Cash Return.
1. Monthly Cash Flow
Cash flow is the net amount of money moving into or out of a business at a specific time. In real estate terms, it is the money left over after all expenses—including the mortgage, taxes, insurance, and maintenance—have been paid from the rental income.
Why it matters: Positive cash flow ensures that the property pays for itself and generates passive income for you. Negative cash flow implies you must contribute money from your own pocket every month to keep the asset.
2. Capitalization Rate (Cap Rate)
The Cap Rate measures the rate of return on a rental investment property based on the income the property is expected to generate. It is calculated by dividing the Net Operating Income (NOI) by the property's current market value.
- Formula: Cap Rate = (Net Operating Income / Property Value) × 100%
- Note: Cap Rate ignores financing (mortgage payments). It is a pure measure of the property's efficiency, making it useful for comparing properties regardless of how they were bought (cash vs. loan).
3. Cash on Cash Return (CoC)
While Cap Rate looks at the property, Cash on Cash Return looks at your money. It measures the annual return you made on the actual cash you invested (down payment and closing costs).
- Formula: CoC = (Annual Pre-Tax Cash Flow / Total Cash Invested) × 100%
- Example: If you invest $50,000 as a down payment and the property generates $5,000 in positive cash flow per year, your Cash on Cash return is 10%. Ideally, this should beat the stock market average (historically 7-8%) to justify the effort of managing real estate.
How to Use This Calculator
To get the most accurate results, ensure you estimate expenses conservatively. "Monthly Expenses" should include property taxes, insurance, HOA fees (if applicable), property management fees (usually 8-10% of rent), and a budget for repairs and vacancy (often estimated at 5-10% of rent each).