.calc-container {
max-width: 800px;
margin: 0 auto;
padding: 25px;
background: #f9f9f9;
border: 1px solid #e0e0e0;
border-radius: 8px;
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}
.calc-header {
text-align: center;
margin-bottom: 25px;
}
.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 {
display: flex;
flex-direction: column;
}
.input-group label {
font-size: 14px;
color: #555;
margin-bottom: 5px;
font-weight: 600;
}
.input-group input {
padding: 10px;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 16px;
}
.input-group input:focus {
border-color: #0073aa;
outline: none;
}
.calc-btn-wrapper {
margin-top: 25px;
text-align: center;
}
.calc-btn {
background-color: #0073aa;
color: white;
border: none;
padding: 12px 30px;
font-size: 18px;
border-radius: 5px;
cursor: pointer;
transition: background 0.3s;
}
.calc-btn:hover {
background-color: #005177;
}
.results-area {
margin-top: 30px;
background: #fff;
padding: 20px;
border-radius: 6px;
border: 1px solid #eee;
display: none; /* Hidden by default */
}
.results-grid {
display: grid;
grid-template-columns: repeat(2, 1fr);
gap: 15px;
}
.result-item {
background: #f0f7fb;
padding: 15px;
border-radius: 4px;
text-align: center;
}
.result-label {
font-size: 13px;
color: #666;
display: block;
margin-bottom: 5px;
}
.result-value {
font-size: 20px;
font-weight: bold;
color: #2c3e50;
}
.result-value.positive {
color: #27ae60;
}
.result-value.negative {
color: #c0392b;
}
.content-section {
max-width: 800px;
margin: 40px auto 0;
font-family: inherit;
line-height: 1.6;
color: #333;
}
.content-section h2 {
color: #2c3e50;
font-size: 28px;
border-bottom: 2px solid #eee;
padding-bottom: 10px;
margin-top: 40px;
}
.content-section h3 {
color: #444;
font-size: 22px;
margin-top: 30px;
}
.content-section p {
margin-bottom: 15px;
}
.content-section ul {
margin-bottom: 20px;
padding-left: 20px;
}
.content-section li {
margin-bottom: 8px;
}
function calculateROI() {
// Get Inputs
var price = parseFloat(document.getElementById('purchasePrice').value);
var down = parseFloat(document.getElementById('downPayment').value);
var closing = parseFloat(document.getElementById('closingCosts').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('monthlyExpenses').value);
// Validation
if (isNaN(price) || isNaN(down) || isNaN(rate) || isNaN(term) || isNaN(rent) || isNaN(expenses)) {
alert("Please enter valid numbers in all fields.");
return;
}
if (isNaN(closing)) { closing = 0; }
// Logic
var loanAmount = price – down;
var monthlyRate = rate / 100 / 12;
var numberOfPayments = term * 12;
// Mortgage Calculation (PMT formula)
// M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
var mortgagePayment = 0;
if (monthlyRate > 0) {
mortgagePayment = (loanAmount * monthlyRate * Math.pow(1 + monthlyRate, numberOfPayments)) / (Math.pow(1 + monthlyRate, numberOfPayments) – 1);
} else {
mortgagePayment = loanAmount / numberOfPayments;
}
// Cash Flow Math
var totalMonthlyCost = mortgagePayment + expenses;
var monthlyCashFlow = rent – totalMonthlyCost;
var annualCashFlow = monthlyCashFlow * 12;
// Cash on Cash Return
// CoC = Annual Pre-Tax Cash Flow / Total Cash Invested
var totalCashInvested = down + closing;
var cocReturn = 0;
if (totalCashInvested > 0) {
cocReturn = (annualCashFlow / totalCashInvested) * 100;
}
// Cap Rate Math
// Cap Rate = Net Operating Income (NOI) / Purchase Price
// NOI = Annual Rent – Annual Expenses (Excluding Mortgage)
var annualNOI = (rent * 12) – (expenses * 12);
var capRate = 0;
if (price > 0) {
capRate = (annualNOI / price) * 100;
}
// Display Results
document.getElementById('resultsArea').style.display = 'block';
document.getElementById('resMortgage').innerText = '$' + mortgagePayment.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
var cashFlowEl = document.getElementById('resCashFlow');
cashFlowEl.innerText = '$' + monthlyCashFlow.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
if (monthlyCashFlow >= 0) {
cashFlowEl.className = 'result-value positive';
} else {
cashFlowEl.className = 'result-value negative';
}
var cocEl = document.getElementById('resCoC');
cocEl.innerText = cocReturn.toFixed(2) + '%';
if (cocReturn >= 0) {
cocEl.className = 'result-value positive';
} else {
cocEl.className = 'result-value negative';
}
document.getElementById('resCapRate').innerText = capRate.toFixed(2) + '%';
}
Understanding Rental Property Investment Analysis
Investing in real estate is a powerful way to build wealth, but simply buying a property and renting it out doesn't guarantee a profit. Successful real estate investors rely on specific financial metrics to evaluate whether a property is a "deal" or a "dud." Our Rental Property ROI Calculator helps you crunch the numbers on potential investments by analyzing the four most critical metrics: Cash Flow, Cash on Cash Return, and Cap Rate.
1. Monthly Cash Flow
Cash flow is the lifeblood of any rental investment. It represents the net amount of money putting into your pocket each month after all expenses are paid. Ideally, you want positive cash flow to cover maintenance and vacancies while generating profit.
The Formula:
Monthly Rent – (Mortgage + Taxes + Insurance + HOA + Repairs) = Cash Flow
If this number is negative, you are losing money every month to hold the property. While some investors bank on appreciation (the property value going up), a negative cash flow property is generally considered risky.
2. Cash on Cash Return (CoC)
Cash on Cash Return is often considered the most important metric for rental investors because it tells you how hard your actual cash is working for you. Unlike a standard ROI which might look at the total loan value, CoC only looks at the money you actually paid out of pocket (Down Payment + Closing Costs).
For example, if you invest $50,000 cash to buy a property and it generates $5,000 in net profit per year, your CoC return is 10%. This allows you to compare real estate returns directly against the stock market or other investments.
3. Capitalization Rate (Cap Rate)
The Cap Rate measures the natural rate of return of the property assuming you bought it entirely with cash (no mortgage). It helps investors compare the profitability of different properties regardless of how they are financed.
The Formula:
Net Operating Income (NOI) / Purchase Price = Cap Rate
Note that NOI includes operating expenses (taxes, insurance, maintenance) but excludes mortgage payments. A higher Cap Rate generally indicates a better return, though it may also come with higher risk or a less desirable location.
How to Use This Calculator
To get the most accurate results from this tool, ensure you include all hidden costs in the "Monthly Expenses" field. Common expenses to include are:
- Property Taxes: Usually 1-2% of the property value annually.
- Insurance: Landlord insurance policies.
- Maintenance/Repairs: A common rule of thumb is to set aside 5-10% of the rent for future repairs.
- Vacancy Rate: Account for months where the unit might sit empty (often calculated as 5-8% of rent).
- Property Management: If you hire a pro, this is typically 8-10% of the monthly rent.