.rental-calculator-wrapper {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
max-width: 800px;
margin: 0 auto;
padding: 20px;
border: 1px solid #e0e0e0;
border-radius: 8px;
background-color: #f9f9f9;
color: #333;
}
.rc-container {
display: flex;
flex-wrap: wrap;
gap: 20px;
}
.rc-column {
flex: 1;
min-width: 300px;
}
.rc-input-group {
margin-bottom: 15px;
}
.rc-input-group label {
display: block;
margin-bottom: 5px;
font-weight: 600;
font-size: 14px;
}
.rc-input-group input, .rc-input-group select {
width: 100%;
padding: 10px;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
.rc-section-title {
font-size: 18px;
font-weight: bold;
margin-bottom: 15px;
color: #2c3e50;
border-bottom: 2px solid #3498db;
padding-bottom: 5px;
}
.rc-btn {
background-color: #27ae60;
color: white;
border: none;
padding: 12px 24px;
font-size: 16px;
font-weight: bold;
border-radius: 4px;
cursor: pointer;
width: 100%;
transition: background-color 0.3s;
}
.rc-btn:hover {
background-color: #219150;
}
.rc-results {
background-color: white;
padding: 20px;
border-radius: 6px;
border: 1px solid #ddd;
margin-top: 20px;
display: none;
}
.rc-result-item {
display: flex;
justify-content: space-between;
margin-bottom: 10px;
padding-bottom: 10px;
border-bottom: 1px dashed #eee;
}
.rc-result-item:last-child {
border-bottom: none;
}
.rc-result-label {
font-weight: 500;
}
.rc-result-value {
font-weight: bold;
color: #2c3e50;
}
.rc-positive {
color: #27ae60;
}
.rc-negative {
color: #c0392b;
}
.rc-highlight {
background-color: #f0f8ff;
padding: 10px;
border-radius: 4px;
margin-top: 5px;
}
.rc-article {
margin-top: 40px;
line-height: 1.6;
}
.rc-article h2 {
font-size: 24px;
margin-bottom: 15px;
color: #2c3e50;
}
.rc-article h3 {
font-size: 20px;
margin-top: 20px;
margin-bottom: 10px;
color: #34495e;
}
.rc-article p {
margin-bottom: 15px;
}
.rc-article ul {
margin-bottom: 15px;
padding-left: 20px;
}
@media (max-width: 600px) {
.rc-container {
flex-direction: column;
}
}
function calculateRentalCashFlow() {
// 1. Get Input Values
var price = parseFloat(document.getElementById("rcPrice").value) || 0;
var closingCosts = parseFloat(document.getElementById("rcClosingCosts").value) || 0;
var downPercent = parseFloat(document.getElementById("rcDownPayment").value) || 0;
var interestRate = parseFloat(document.getElementById("rcInterestRate").value) || 0;
var termYears = parseFloat(document.getElementById("rcLoanTerm").value) || 30;
var monthlyRent = parseFloat(document.getElementById("rcRent").value) || 0;
var annualTax = parseFloat(document.getElementById("rcPropTax").value) || 0;
var annualInsurance = parseFloat(document.getElementById("rcInsurance").value) || 0;
var monthlyHOA = parseFloat(document.getElementById("rcHOA").value) || 0;
var maintPercent = parseFloat(document.getElementById("rcMaint").value) || 0;
// 2. Initial Calculations
var downPaymentAmount = price * (downPercent / 100);
var loanAmount = price – downPaymentAmount;
var totalCashInvested = downPaymentAmount + closingCosts;
// 3. Mortgage Calculation (Amortization)
var monthlyMortgage = 0;
if (loanAmount > 0 && interestRate > 0) {
var monthlyRate = (interestRate / 100) / 12;
var numPayments = termYears * 12;
monthlyMortgage = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, numPayments)) / (Math.pow(1 + monthlyRate, numPayments) – 1);
} else if (loanAmount > 0 && interestRate === 0) {
monthlyMortgage = loanAmount / (termYears * 12);
}
// 4. Expense Calculations
var monthlyTax = annualTax / 12;
var monthlyInsurance = annualInsurance / 12;
var monthlyMaintVacancy = monthlyRent * (maintPercent / 100);
// Operating Expenses (Expenses excluding mortgage)
var monthlyOperatingExpenses = monthlyTax + monthlyInsurance + monthlyHOA + monthlyMaintVacancy;
// Total Expenses (Operating + Mortgage)
var totalMonthlyExpenses = monthlyOperatingExpenses + monthlyMortgage;
// 5. Profitability Calculations
var monthlyCashFlow = monthlyRent – totalMonthlyExpenses;
var annualCashFlow = monthlyCashFlow * 12;
// Net Operating Income (Annual) = (Income – Operating Expenses) * 12
var annualNOI = (monthlyRent – monthlyOperatingExpenses) * 12;
// Cash on Cash Return = (Annual Cash Flow / Total Cash Invested) * 100
var cashOnCash = 0;
if (totalCashInvested > 0) {
cashOnCash = (annualCashFlow / totalCashInvested) * 100;
}
// Cap Rate = (Annual NOI / Purchase Price) * 100
var capRate = 0;
if (price > 0) {
capRate = (annualNOI / price) * 100;
}
// 6. Formatting Helper
var formatCurrency = function(num) {
return "$" + num.toFixed(2).replace(/\d(?=(\d{3})+\.)/g, '$&,');
};
// 7. Update UI
document.getElementById("resIncome").innerText = formatCurrency(monthlyRent);
document.getElementById("resExpenses").innerText = formatCurrency(totalMonthlyExpenses);
document.getElementById("resMortgage").innerText = formatCurrency(monthlyMortgage);
var cashFlowEl = document.getElementById("resCashFlow");
cashFlowEl.innerText = formatCurrency(monthlyCashFlow);
if (monthlyCashFlow >= 0) {
cashFlowEl.className = "rc-result-value rc-positive";
} else {
cashFlowEl.className = "rc-result-value rc-negative";
}
document.getElementById("resCoC").innerText = cashOnCash.toFixed(2) + "%";
document.getElementById("resCapRate").innerText = capRate.toFixed(2) + "%";
document.getElementById("resNOI").innerText = formatCurrency(annualNOI);
document.getElementById("resCashNeeded").innerText = formatCurrency(totalCashInvested);
// Show results
document.getElementById("rcResults").style.display = "block";
}
Property Details
Loan Details
15 Years
30 Years
Income & Expenses
Investment Analysis
Monthly Cash Flow:
$0.00
Monthly Income:
$0.00
Total Monthly Expenses:
$0.00
Monthly Mortgage P&I:
$0.00
Performance Metrics
Cash on Cash Return (ROI):
0.00%
Cap Rate:
0.00%
Net Operating Income (Annual):
$0.00
Total Cash Needed to Close:
$0.00
How to Analyze Rental Property Investments
Investing in real estate is one of the most reliable ways to build wealth, but simply buying a property doesn't guarantee profit. To succeed, you must understand the numbers behind the deal. This Rental Property Calculator helps investors evaluate the potential profitability of a real estate asset by breaking down income, expenses, and return metrics.
Key Metrics Explained
- Cash Flow: This is the net profit you pocket every month after all expenses (mortgage, taxes, insurance, maintenance) are paid. Positive cash flow ensures the property pays for itself and generates income.
- Cash on Cash Return (CoC): This percentage tells you how hard your money is working. It measures the annual cash flow relative to the total cash you actually invested (down payment + closing costs). A CoC of 8-12% is generally considered a solid return in many markets.
- Cap Rate (Capitalization Rate): The Cap Rate measures the natural rate of return of the property independent of financing. It is calculated by dividing the Net Operating Income (NOI) by the purchase price. It helps compare properties regardless of how they are purchased (cash vs. loan).
- Net Operating Income (NOI): This is the total income the property generates minus all operating expenses. Crucially, NOI does not include mortgage payments. Lenders look at NOI to determine if a property can support debt payments.
How to Use This Calculator
Start by entering the Property Details, such as the purchase price and your expected closing costs. Next, configure your Loan Details. The interest rate and loan term will significantly impact your monthly mortgage payment and, consequently, your cash flow.
In the Income & Expenses section, be realistic. Don't just account for the mortgage; ensure you include property taxes, insurance, HOA fees, and a buffer for maintenance and vacancy (typically 5-10% of rent). Underestimating expenses is the #1 mistake new investors make.
Example Scenario
Imagine purchasing a property for $250,000 with a 20% down payment ($50,000). If you rent it out for $2,200/month and your total monthly expenses (mortgage + taxes + repairs) come to $1,900, your monthly cash flow is $300. While $300 might seem small, if your initial investment was $55,000 (down payment + closing), your annual Cash on Cash return is roughly 6.5%. Over time, as rent increases and the mortgage is paid down, this return typically improves.