#rental-property-calculator-plugin {
font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
max-width: 800px;
margin: 0 auto;
color: #333;
line-height: 1.6;
}
.rpc-calculator-box {
background: #f9fbfd;
border: 1px solid #e1e4e8;
border-radius: 8px;
padding: 30px;
margin-bottom: 40px;
box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}
.rpc-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
}
@media (max-width: 600px) {
.rpc-grid {
grid-template-columns: 1fr;
}
}
.rpc-input-group {
margin-bottom: 15px;
}
.rpc-input-group label {
display: block;
font-weight: 600;
margin-bottom: 5px;
font-size: 0.9em;
color: #2c3e50;
}
.rpc-input-group input, .rpc-input-group select {
width: 100%;
padding: 10px;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
.rpc-section-title {
grid-column: 1 / -1;
font-size: 1.2em;
font-weight: 700;
color: #0073aa;
margin-top: 10px;
margin-bottom: 10px;
border-bottom: 2px solid #e1e4e8;
padding-bottom: 5px;
}
.rpc-btn {
grid-column: 1 / -1;
background-color: #0073aa;
color: white;
border: none;
padding: 15px;
font-size: 18px;
font-weight: bold;
border-radius: 5px;
cursor: pointer;
transition: background 0.3s;
margin-top: 10px;
width: 100%;
}
.rpc-btn:hover {
background-color: #005177;
}
#rpc-results {
grid-column: 1 / -1;
background: #fff;
border: 1px solid #dcdcdc;
padding: 20px;
border-radius: 5px;
margin-top: 20px;
display: none;
}
.rpc-result-row {
display: flex;
justify-content: space-between;
padding: 8px 0;
border-bottom: 1px solid #eee;
}
.rpc-result-row:last-child {
border-bottom: none;
}
.rpc-result-label {
color: #555;
}
.rpc-result-value {
font-weight: bold;
color: #333;
}
.rpc-highlight {
font-size: 1.2em;
color: #27ae60;
}
.rpc-highlight-negative {
font-size: 1.2em;
color: #c0392b;
}
.rpc-article h2 {
color: #2c3e50;
border-bottom: 2px solid #0073aa;
padding-bottom: 10px;
margin-top: 40px;
}
.rpc-article h3 {
color: #34495e;
margin-top: 25px;
}
.rpc-article p {
margin-bottom: 15px;
}
.rpc-article ul {
margin-bottom: 20px;
padding-left: 20px;
}
.rpc-article li {
margin-bottom: 8px;
}
function calculateRentalCashFlow() {
// 1. Get Inputs
var price = parseFloat(document.getElementById('rpc-price').value) || 0;
var downPayment = parseFloat(document.getElementById('rpc-down').value) || 0;
var closingCosts = parseFloat(document.getElementById('rpc-closing').value) || 0;
var interestRate = parseFloat(document.getElementById('rpc-interest').value) || 0;
var loanTermYears = parseFloat(document.getElementById('rpc-term').value) || 30;
var rent = parseFloat(document.getElementById('rpc-rent').value) || 0;
var vacancyRate = parseFloat(document.getElementById('rpc-vacancy').value) || 0;
var tax = parseFloat(document.getElementById('rpc-tax').value) || 0;
var insurance = parseFloat(document.getElementById('rpc-insurance').value) || 0;
var hoa = parseFloat(document.getElementById('rpc-hoa').value) || 0;
var maintenanceRate = parseFloat(document.getElementById('rpc-maintenance').value) || 0;
// 2. Calculate Mortgage (Principal + Interest)
var loanAmount = price – downPayment;
var monthlyInterestRate = (interestRate / 100) / 12;
var numberOfPayments = loanTermYears * 12;
var monthlyMortgage = 0;
if (interestRate > 0 && loanAmount > 0) {
monthlyMortgage = loanAmount * (monthlyInterestRate * Math.pow(1 + monthlyInterestRate, numberOfPayments)) / (Math.pow(1 + monthlyInterestRate, numberOfPayments) – 1);
} else if (loanAmount > 0) {
monthlyMortgage = loanAmount / numberOfPayments;
}
// 3. Calculate Operating Expenses
var vacancyCost = rent * (vacancyRate / 100);
var maintenanceCost = rent * (maintenanceRate / 100);
var totalOperatingExpenses = tax + insurance + hoa + vacancyCost + maintenanceCost;
// 4. Calculate Cash Flow
var totalMonthlyExpenses = monthlyMortgage + totalOperatingExpenses;
var monthlyCashFlow = rent – totalMonthlyExpenses;
var annualCashFlow = monthlyCashFlow * 12;
// 5. Calculate Returns
var totalInvestment = downPayment + closingCosts;
var cashOnCash = 0;
if (totalInvestment > 0) {
cashOnCash = (annualCashFlow / totalInvestment) * 100;
}
// Cap Rate (NOI / Price)
// NOI = Annual Rent – Annual Operating Expenses (Excluding Mortgage)
var annualNOI = (rent * 12) – (totalOperatingExpenses * 12);
var capRate = 0;
if (price > 0) {
capRate = (annualNOI / price) * 100;
}
// 6. Update UI
document.getElementById('res-mortgage').innerText = '$' + monthlyMortgage.toFixed(2);
document.getElementById('res-expenses').innerText = '$' + totalOperatingExpenses.toFixed(2);
document.getElementById('res-noi').innerText = '$' + (annualNOI / 12).toFixed(2); // Monthly NOI
var cashFlowEl = document.getElementById('res-cashflow');
cashFlowEl.innerText = '$' + monthlyCashFlow.toFixed(2);
if (monthlyCashFlow >= 0) {
cashFlowEl.className = 'rpc-result-value rpc-highlight';
} else {
cashFlowEl.className = 'rpc-result-value rpc-highlight-negative';
}
var cocEl = document.getElementById('res-coc');
cocEl.innerText = cashOnCash.toFixed(2) + '%';
cocEl.style.color = cashOnCash >= 0 ? '#27ae60' : '#c0392b';
document.getElementById('res-cap').innerText = capRate.toFixed(2) + '%';
// Show results div
document.getElementById('rpc-results').style.display = 'grid';
}
Purchase Information
30 Years
15 Years
10 Years
Rental Income
Monthly Expenses
Monthly Mortgage (P&I):
$0.00
Total Monthly Expenses:
$0.00
Net Operating Income (NOI):
$0.00
Monthly Cash Flow:
$0.00
Cash on Cash Return:
0.00%
Cap Rate:
0.00%
Understanding Rental Property Profitability
Investing in real estate is one of the most reliable ways to build wealth, but simply buying a property and renting it out doesn't guarantee a profit. To succeed, investors must meticulously analyze the numbers. This Rental Property Cash Flow Calculator helps you evaluate the potential profitability of an investment property by factoring in income, expenses, financing costs, and vacancy rates.
Key Metrics Explained
When analyzing a deal, experienced investors look at three primary metrics which this calculator computes for you:
- Cash Flow: This is the net profit you pocket every month after all bills are paid. It is calculated as Total Income – (Mortgage + Expenses). Positive cash flow ensures the property pays for itself and provides passive income.
- Cash on Cash Return (CoC): This measures the return on the actual cash you invested (down payment + closing costs). It is a crucial metric for comparing real estate returns against other investment vehicles like stocks. A CoC of 8-12% is generally considered good in many markets.
- Cap Rate (Capitalization Rate): This indicates the rate of return on a real estate investment property based on the income that the property is expected to generate, ignoring the financing method. It helps compare properties regardless of how they were bought (cash vs. loan).
How to Calculate Accurate Expenses
One of the most common mistakes new investors make is underestimating expenses. Beyond the obvious mortgage, tax, and insurance payments, you must account for:
- Vacancy: Your property won't be rented 365 days a year. Allocating 5-8% of the monthly rent for vacancy ensures you have a buffer for turnover periods.
- Maintenance & Repairs: Things break. Setting aside 5-10% of the rent creates a "Capex" (Capital Expenditures) fund for when you need to replace a water heater or repair a roof.
- Property Management: Even if you plan to self-manage initially, it is wise to calculate the numbers assuming a 10% property management fee. If the deal still works with that fee, it's a solid investment.
Using the 1% Rule
A quick rule of thumb used by investors for initial screening is the "1% Rule." It suggests that the monthly rent should be at least 1% of the purchase price. For example, a $200,000 home should rent for at least $2,000/month. While not a hard rule, it helps quickly filter out properties that are unlikely to cash flow positively.