.calculator-wrapper {
max-width: 800px;
margin: 0 auto;
font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
color: #333;
line-height: 1.6;
}
.calc-container {
background-color: #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-title {
text-align: center;
color: #2c3e50;
margin-bottom: 25px;
font-size: 24px;
font-weight: 700;
}
.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;
font-size: 14px;
}
.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: #3498db;
outline: none;
}
.btn-calc {
display: block;
width: 100%;
background-color: #27ae60;
color: white;
border: none;
padding: 15px;
font-size: 18px;
font-weight: bold;
border-radius: 4px;
cursor: pointer;
transition: background 0.3s;
margin-top: 10px;
}
.btn-calc:hover {
background-color: #219150;
}
.results-section {
background-color: #fff;
border: 1px solid #dee2e6;
border-radius: 6px;
padding: 20px;
margin-top: 25px;
display: none;
}
.result-row {
display: flex;
justify-content: space-between;
padding: 10px 0;
border-bottom: 1px solid #eee;
}
.result-row:last-child {
border-bottom: none;
}
.result-label {
font-weight: 600;
color: #555;
}
.result-value {
font-weight: 700;
font-size: 18px;
}
.value-positive {
color: #27ae60;
}
.value-negative {
color: #c0392b;
}
.article-content {
margin-top: 50px;
padding: 20px;
background: #fff;
}
.article-content h2 {
color: #2c3e50;
border-bottom: 2px solid #3498db;
padding-bottom: 10px;
margin-top: 30px;
}
.article-content h3 {
color: #34495e;
margin-top: 25px;
}
.article-content p, .article-content li {
font-size: 16px;
color: #444;
margin-bottom: 15px;
}
.tip-box {
background-color: #e8f4fd;
border-left: 4px solid #3498db;
padding: 15px;
margin: 20px 0;
font-style: italic;
}
function calculateRentalROI() {
// Get inputs
var price = parseFloat(document.getElementById('purchasePrice').value);
var downPmt = parseFloat(document.getElementById('downPayment').value);
var rate = parseFloat(document.getElementById('interestRate').value);
var years = parseFloat(document.getElementById('loanTerm').value);
var rent = parseFloat(document.getElementById('monthlyRent').value);
var expenses = parseFloat(document.getElementById('monthlyExpenses').value);
// Validation
if (isNaN(price) || isNaN(downPmt) || isNaN(rate) || isNaN(years) || isNaN(rent) || isNaN(expenses)) {
alert("Please fill in all fields with valid numbers.");
return;
}
// Loan Logic
var loanAmount = price – downPmt;
var monthlyRate = rate / 100 / 12;
var numberOfPayments = years * 12;
// Mortgage Payment (P&I) Formula
var mortgagePayment = 0;
if (rate > 0) {
mortgagePayment = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, numberOfPayments)) / (Math.pow(1 + monthlyRate, numberOfPayments) – 1);
} else {
mortgagePayment = loanAmount / numberOfPayments;
}
// Monthly Analysis
var totalMonthlyCost = mortgagePayment + expenses;
var monthlyCashFlow = rent – totalMonthlyCost;
var annualCashFlow = monthlyCashFlow * 12;
// Annual Net Operating Income (Rent – Operating Expenses)
// Note: NOI does NOT include mortgage interest/payments
var annualNOI = (rent – expenses) * 12;
// Returns Analysis
var cashInvested = downPmt; // Assuming no closing costs for simplicity, or user adds to down payment
var cocReturn = 0;
if (cashInvested > 0) {
cocReturn = (annualCashFlow / cashInvested) * 100;
}
var capRate = 0;
if (price > 0) {
capRate = (annualNOI / price) * 100;
}
// Display Results
document.getElementById('resMortgage').innerText = "$" + mortgagePayment.toFixed(2);
var cfElement = document.getElementById('resCashFlow');
cfElement.innerText = "$" + monthlyCashFlow.toFixed(2);
cfElement.className = "result-value " + (monthlyCashFlow >= 0 ? "value-positive" : "value-negative");
document.getElementById('resNOI').innerText = "$" + annualNOI.toFixed(2);
var cocElement = document.getElementById('resCoC');
cocElement.innerText = cocReturn.toFixed(2) + "%";
cocElement.className = "result-value " + (cocReturn >= 0 ? "value-positive" : "value-negative");
document.getElementById('resCapRate').innerText = capRate.toFixed(2) + "%";
// Show results div
document.getElementById('results').style.display = "block";
}
Understanding Rental Property Cash Flow
Investing in real estate is one of the most reliable ways to build wealth, but simply buying a property doesn't guarantee profit. The key to successful real estate investing lies in the numbers. This Rental Property Cash Flow Calculator is designed to help investors quickly analyze the viability of a potential investment property by looking at critical metrics like Monthly Cash Flow, Cash on Cash Return, and Cap Rate.
What is Cash Flow?
Cash flow is the net amount of cash moving in and out of an investment. In rental properties, it is calculated as your Total Rental Income minus your Total Expenses (including mortgage payments, taxes, insurance, and maintenance). Positive cash flow means the property is putting money into your pocket every month, while negative cash flow means you are paying out of pocket to hold the asset.
Pro Tip: Most seasoned investors aim for at least $100–$200 in positive cash flow per door per month to ensure a safety margin against vacancies and unexpected repairs.
Key Metrics Explained
1. Net Operating Income (NOI)
NOI is a calculation used to analyze the profitability of income-generating real estate investments. NOI equals all revenue from the property, minus all reasonably necessary operating expenses. Importantly, NOI is a before-tax figure and excludes principal and interest payments on loans. It helps determine the intrinsic value of the property independent of financing.
2. Cash on Cash Return (CoC)
This is perhaps the most important metric for leverage investors. It measures the annual return the investor made on the property in relation to the amount of mortgage paid during the same year. It is calculated as:
(Annual Pre-Tax Cash Flow / Total Cash Invested) x 100
For example, if you invest $50,000 as a down payment and the property generates $5,000 in net cash flow per year, your Cash on Cash return is 10%.
3. Capitalization Rate (Cap Rate)
The Cap Rate indicates the rate of return that is expected to be generated on a real estate investment property. It is calculated by dividing the Net Operating Income (NOI) by the property asset value. Unlike Cash on Cash return, Cap Rate ignores financing, allowing you to compare properties directly regardless of how they are purchased (cash vs. loan).
How to Estimate Expenses
One of the biggest mistakes new investors make is underestimating expenses. When using the calculator above, ensure your "Monthly Expenses" field includes:
- Property Taxes: Generally 1-2% of the property value annually.
- Insurance: Fire and hazard insurance.
- Maintenance & Repairs: Rule of thumb is to budget 1% of the property value per year.
- Vacancy Rate: Assume the property will sit empty for at least 5-8% of the year.
- Property Management: If you hire a manager, deduct 8-10% of the rent.
Using the Rental Calculator
To use this tool effectively, gather accurate data from the seller or your real estate agent. Input the purchase price and your financing terms. Be realistic with your rental income projections by comparing similar properties in the neighborhood (comps). Once you calculate, look for a positive Cash on Cash return that beats the stock market average (typically 7-10%) to justify the illiquidity and effort of real estate investing.