/* Scoped Styles for Calculator */
.calc-container {
max-width: 800px;
margin: 20px auto;
font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
border: 1px solid #e0e0e0;
border-radius: 8px;
box-shadow: 0 4px 12px rgba(0,0,0,0.05);
background: #ffffff;
padding: 0;
overflow: hidden;
}
.calc-header {
background: #2c3e50;
color: #fff;
padding: 20px;
text-align: center;
}
.calc-header h2 {
margin: 0;
font-size: 24px;
}
.calc-body {
padding: 25px;
display: flex;
flex-wrap: wrap;
gap: 30px;
}
.calc-inputs {
flex: 1;
min-width: 300px;
}
.calc-results {
flex: 1;
min-width: 300px;
background: #f8f9fa;
border-radius: 6px;
padding: 20px;
border: 1px solid #e9ecef;
}
.input-group {
margin-bottom: 15px;
}
.input-group label {
display: block;
margin-bottom: 5px;
font-weight: 600;
font-size: 14px;
color: #34495e;
}
.input-group input {
width: 100%;
padding: 10px;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box; /* Important for padding */
}
.input-group input:focus {
border-color: #3498db;
outline: none;
}
.calc-btn {
width: 100%;
padding: 12px;
background: #27ae60;
color: white;
border: none;
border-radius: 4px;
font-size: 18px;
font-weight: bold;
cursor: pointer;
transition: background 0.3s;
margin-top: 10px;
}
.calc-btn:hover {
background: #219150;
}
.result-row {
display: flex;
justify-content: space-between;
margin-bottom: 12px;
padding-bottom: 12px;
border-bottom: 1px solid #dee2e6;
font-size: 15px;
}
.result-row:last-child {
border-bottom: none;
}
.result-label {
color: #7f8c8d;
}
.result-value {
font-weight: 700;
color: #2c3e50;
}
.highlight-result {
background-color: #e8f5e9;
padding: 10px;
border-radius: 4px;
margin-top: 10px;
}
.highlight-result .result-value {
color: #27ae60;
font-size: 18px;
}
/* SEO Content Styling */
.seo-content {
max-width: 800px;
margin: 40px auto;
font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
line-height: 1.6;
color: #333;
}
.seo-content h2 {
color: #2c3e50;
border-bottom: 2px solid #27ae60;
padding-bottom: 10px;
margin-top: 40px;
}
.seo-content h3 {
color: #34495e;
margin-top: 30px;
}
.seo-content p {
margin-bottom: 15px;
}
.seo-content ul {
margin-bottom: 20px;
}
.seo-content li {
margin-bottom: 8px;
}
.seo-table {
width: 100%;
border-collapse: collapse;
margin: 20px 0;
}
.seo-table th, .seo-table td {
border: 1px solid #ddd;
padding: 12px;
text-align: left;
}
.seo-table th {
background-color: #f2f2f2;
}
function calculateRentalROI() {
// 1. Get Input Values
var price = parseFloat(document.getElementById('purchasePrice').value);
var downPercent = parseFloat(document.getElementById('downPaymentPercent').value);
var rate = parseFloat(document.getElementById('interestRate').value);
var term = parseFloat(document.getElementById('loanTerm').value);
var closing = parseFloat(document.getElementById('closingCosts').value);
var rent = parseFloat(document.getElementById('monthlyRent').value);
var expenses = parseFloat(document.getElementById('monthlyExpenses').value);
// Validation to prevent NaN errors
if (isNaN(price) || isNaN(downPercent) || isNaN(rate) || isNaN(term) || isNaN(rent) || isNaN(expenses)) {
alert("Please enter valid numbers in all fields.");
return;
}
// 2. Perform Calculations
// Loan Calculation
var downPaymentAmount = price * (downPercent / 100);
var loanAmount = price – downPaymentAmount;
var monthlyRate = (rate / 100) / 12;
var numberOfPayments = term * 12;
// Mortgage Payment Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
var monthlyMortgage = 0;
if (rate > 0) {
monthlyMortgage = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, numberOfPayments)) / (Math.pow(1 + monthlyRate, numberOfPayments) – 1);
} else {
monthlyMortgage = loanAmount / numberOfPayments;
}
// Income & Expense Logic
var totalMonthlyExpenses = monthlyMortgage + expenses;
var monthlyCashFlow = rent – totalMonthlyExpenses;
var annualCashFlow = monthlyCashFlow * 12;
// NOI Logic (Net Operating Income excludes financing costs)
var annualNOI = (rent – expenses) * 12;
// Investment Returns
var totalInitialInvestment = downPaymentAmount + closing;
// CoC Return = Annual Cash Flow / Total Cash Invested
var cocReturn = 0;
if (totalInitialInvestment > 0) {
cocReturn = (annualCashFlow / totalInitialInvestment) * 100;
}
// Cap Rate = NOI / Purchase Price
var capRate = 0;
if (price > 0) {
capRate = (annualNOI / price) * 100;
}
// 3. Update DOM with Results
// Helper function for currency formatting
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
minimumFractionDigits: 2
});
document.getElementById('res_mortgage').innerText = formatter.format(monthlyMortgage);
document.getElementById('res_cashFlow').innerText = formatter.format(monthlyCashFlow);
document.getElementById('res_totalInvestment').innerText = formatter.format(totalInitialInvestment);
document.getElementById('res_noi').innerText = formatter.format(annualNOI);
// Update percentages
document.getElementById('res_coc').innerText = cocReturn.toFixed(2) + "%";
document.getElementById('res_capRate').innerText = capRate.toFixed(2) + "%";
// Visual feedback based on Cash Flow
var cfElement = document.getElementById('res_cashFlow');
if (monthlyCashFlow >= 0) {
cfElement.style.color = "#27ae60";
} else {
cfElement.style.color = "#c0392b";
}
}
// Initialize calculation on load
calculateRentalROI();
Mastering Rental Property Analysis
Real estate investment is one of the most reliable pathways to wealth generation, but success hinges on the numbers. Unlike emotional home buying, investing in rental properties requires a cold, hard look at the data. This Rental Property Cash Flow Calculator helps investors analyze the profitability of a potential deal by breaking down the three critical metrics: Cash Flow, Cash-on-Cash Return, and Cap Rate.
Why You Need a Specialized Calculator
A standard mortgage calculator only tells you what you owe the bank. It ignores the operating expenses (taxes, insurance, maintenance, vacancy) and the income the property generates. To make an informed decision, you must calculate the Net Operating Income (NOI) and compare it against your debt service to determine if an asset is an asset or a liability.
Key Metrics Explained
1. Monthly Cash Flow
Cash flow is the net amount of money moving into or out of a business, project, or financial product. For a rental property, it is calculated as:
Monthly Rent – (Mortgage Payment + All Operating Expenses) = Cash Flow
Positive cash flow means the property pays for itself and puts money in your pocket every month. Negative cash flow means you are losing money to hold the property.
2. Cash-on-Cash Return (CoC)
This is arguably the most important metric for leverage-based investors. It measures the annual return you made on the actual cash you invested (Down Payment + Closing Costs), not the total price of the home.
- Formula: (Annual Pre-Tax Cash Flow / Total Cash Invested) × 100
- Good Target: Many investors aim for 8-12% CoC, though this varies by market.
3. Capitalization Rate (Cap Rate)
The Cap Rate measures the property's natural rate of return assuming you bought it for cash. It helps compare properties regardless of financing.
- Formula: (Net Operating Income / Purchase Price) × 100
- Use Case: Use Cap Rate to compare the raw profitability of two different buildings.
How to Use This Calculator
To get the most accurate results, ensure you input realistic data:
| Input Field |
Description |
Typical Value |
| Purchase Price |
The agreed-upon sale price of the property. |
Market Dependent |
| Loan Term |
Duration of the mortgage. |
30 Years |
| Monthly Expenses |
Sum of Property Taxes, Insurance, HOA, Maintenance, and Vacancy reserves. |
30-50% of Rent |
| Closing Costs |
Fees paid at the closing of a real estate transaction. |
2-5% of Price |
Frequently Asked Questions (FAQ)
What is the 1% Rule in real estate?
The 1% rule is a quick rule of thumb used to screen rental properties. It suggests that the monthly rent should be at least 1% of the purchase price. For example, a $200,000 home should rent for $2,000/month. While hard to find in today's market, properties meeting this rule often have strong cash flow.
Should I include vacancy rates in my expenses?
Yes. Even in hot markets, tenants move out. A standard practice is to allocate 5% to 8% of the monthly rent as a vacancy allowance in your "Monthly Expenses" field to ensure your calculations are conservative.
What is a "good" Cash-on-Cash return?
This is subjective. The stock market historically returns about 7-10% (adjusted for inflation). Therefore, real estate investors often look for CoC returns that exceed this benchmark, typically aiming for 10% or higher to justify the lack of liquidity and the effort of management.