.calculator-container {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
max-width: 800px;
margin: 0 auto;
color: #333;
}
.calc-box {
background: #f8f9fa;
border: 1px solid #e9ecef;
border-radius: 8px;
padding: 30px;
box-shadow: 0 4px 6px rgba(0,0,0,0.05);
margin-bottom: 40px;
}
.calc-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
}
.input-group {
margin-bottom: 15px;
}
.input-group label {
display: block;
font-weight: 600;
margin-bottom: 8px;
color: #495057;
font-size: 0.95em;
}
.input-group input {
width: 100%;
padding: 10px;
border: 1px solid #ced4da;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
.input-group input:focus {
border-color: #4dabf7;
outline: none;
box-shadow: 0 0 0 3px rgba(77, 171, 247, 0.2);
}
.calc-btn {
grid-column: span 2;
background: #228be6;
color: white;
border: none;
padding: 15px;
font-size: 18px;
font-weight: bold;
border-radius: 4px;
cursor: pointer;
transition: background 0.2s;
margin-top: 10px;
}
.calc-btn:hover {
background: #1c7ed6;
}
.results-box {
grid-column: span 2;
background: #fff;
border: 1px solid #dee2e6;
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 #f1f3f5;
}
.result-row:last-child {
border-bottom: none;
}
.result-label {
color: #868e96;
font-weight: 500;
}
.result-value {
font-weight: 700;
font-size: 1.1em;
color: #212529;
}
.highlight-result {
color: #2f9e44;
font-size: 1.2em;
}
.article-content {
line-height: 1.6;
color: #444;
}
.article-content h2 {
color: #343a40;
margin-top: 30px;
font-size: 1.8em;
}
.article-content h3 {
color: #495057;
margin-top: 25px;
font-size: 1.4em;
}
.article-content ul {
padding-left: 20px;
}
.article-content li {
margin-bottom: 10px;
}
.example-box {
background: #e7f5ff;
padding: 20px;
border-left: 4px solid #228be6;
margin: 20px 0;
}
@media (max-width: 600px) {
.calc-grid {
grid-template-columns: 1fr;
}
.calc-btn, .results-box {
grid-column: span 1;
}
}
function calculateRentalROI() {
// Get inputs
var price = parseFloat(document.getElementById('propPrice').value);
var downPerc = parseFloat(document.getElementById('downPayment').value);
var rate = parseFloat(document.getElementById('interestRate').value);
var term = parseFloat(document.getElementById('loanTerm').value);
var rent = parseFloat(document.getElementById('monthlyRent').value);
var expenses = parseFloat(document.getElementById('monthlyCosts').value);
// Validation
if (isNaN(price) || isNaN(downPerc) || isNaN(rate) || isNaN(term) || isNaN(rent) || isNaN(expenses)) {
alert("Please fill in all fields with valid numbers.");
return;
}
// Loan Calculations
var downPaymentAmt = price * (downPerc / 100);
var loanAmount = price – downPaymentAmt;
var monthlyRate = (rate / 100) / 12;
var numberOfPayments = term * 12;
// Mortgage Payment Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
// If rate is 0, handle simple division
var mortgagePayment = 0;
if (rate === 0) {
mortgagePayment = loanAmount / numberOfPayments;
} else {
mortgagePayment = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, numberOfPayments)) / (Math.pow(1 + monthlyRate, numberOfPayments) – 1);
}
// Cash Flow Calculations
var totalMonthlyExpenses = mortgagePayment + expenses;
var monthlyCashFlow = rent – totalMonthlyExpenses;
var annualCashFlow = monthlyCashFlow * 12;
// NOI (Net Operating Income) Calculation (Income – Operating Expenses, excluding mortgage)
var annualOperatingExpenses = expenses * 12;
var annualIncome = rent * 12;
var noi = annualIncome – annualOperatingExpenses;
// Cap Rate Calculation: (NOI / Purchase Price) * 100
var capRate = (noi / price) * 100;
// Cash on Cash ROI: (Annual Cash Flow / Cash Invested) * 100
// Assuming Cash Invested is just Down Payment for this simple tool (excludes closing costs for simplicity)
var cashOnCash = (annualCashFlow / downPaymentAmt) * 100;
// Display Results
document.getElementById('resMortgage').innerHTML = "$" + mortgagePayment.toFixed(2).replace(/\d(?=(\d{3})+\.)/g, '$&,');
document.getElementById('resTotalExp').innerHTML = "$" + totalMonthlyExpenses.toFixed(2).replace(/\d(?=(\d{3})+\.)/g, '$&,');
document.getElementById('resNOI').innerHTML = "$" + noi.toFixed(2).replace(/\d(?=(\d{3})+\.)/g, '$&,');
var cashFlowElem = document.getElementById('resCashFlow');
cashFlowElem.innerHTML = "$" + monthlyCashFlow.toFixed(2).replace(/\d(?=(\d{3})+\.)/g, '$&,');
cashFlowElem.style.color = monthlyCashFlow >= 0 ? '#2f9e44' : '#e03131';
document.getElementById('resCapRate').innerHTML = capRate.toFixed(2) + "%";
var cocElem = document.getElementById('resCoC');
cocElem.innerHTML = cashOnCash.toFixed(2) + "%";
cocElem.style.color = cashOnCash >= 0 ? '#2f9e44' : '#e03131';
// Show results div
document.getElementById('resultsDisplay').style.display = 'block';
}
Rental Property ROI Calculator
Monthly Mortgage Payment (P&I):
$0.00
Total Monthly Cash Outflow:
$0.00
Net Operating Income (Annual):
$0.00
Monthly Cash Flow:
$0.00
Cap Rate:
0.00%
Cash on Cash ROI:
0.00%
How to Calculate Rental Property ROI
Investing in real estate is one of the most reliable ways to build wealth, but not every property is a good deal. To accurately assess the profitability of a potential investment, you need to look beyond the purchase price and calculate your Return on Investment (ROI). This Rental Property ROI Calculator helps you analyze cash flow, Cap Rate, and Cash on Cash return to ensure you make data-driven decisions.
Key Metrics Explained
- Cash Flow: This is the net amount of money left in your pocket each month after all operating expenses and mortgage payments are made. Positive cash flow is essential for a sustainable investment.
- Cap Rate (Capitalization Rate): This metric calculates the rate of return on the property based on the income it generates, exclusive of financing. It is calculated as Net Operating Income (NOI) / Purchase Price. It allows you to compare properties regardless of how they are financed.
- Cash on Cash ROI: This is arguably the most important metric for investors using leverage (mortgages). It measures the annual cash return on the actual cash you invested (down payment + closing costs). A healthy Cash on Cash return typically ranges from 8% to 12% or higher.
Real-World Calculation Example
Let's look at a realistic scenario to understand how the math works. Suppose you are buying a single-family home to rent out.
Example Scenario:
- Purchase Price: $250,000
- Down Payment: 20% ($50,000)
- Interest Rate: 6.5% on a 30-year fixed loan
- Monthly Rent: $2,200
- Monthly Expenses: $600 (Taxes, Insurance, HOA, Maintenance reserves)
The Math:
1. Loan Amount: $200,000 ($250k – $50k down).
2. Mortgage Payment: Approximately $1,264.14 per month.
3. Total Monthly Outflow: $1,264.14 (Mortgage) + $600 (Expenses) = $1,864.14.
4. Monthly Cash Flow: $2,200 (Rent) – $1,864.14 (Outflow) = $335.86.
5. Annual Cash Flow: $335.86 × 12 = $4,030.32.
6. Cash on Cash ROI: $4,030.32 / $50,000 = 8.06%.
Why You Should Estimate Expenses Conservatively
A common mistake new investors make is underestimating monthly expenses. When using the calculator above, ensure your "Monthly Expenses" input includes property taxes, landlord insurance, HOA fees, and an allocation for vacancy and repairs (typically 5-10% of rent). Underestimating these costs can make a negative cash flow property appear profitable on paper.