.rp-calculator-wrapper {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
max-width: 800px;
margin: 20px auto;
padding: 30px;
background: #ffffff;
border-radius: 12px;
box-shadow: 0 4px 20px rgba(0,0,0,0.08);
border: 1px solid #e0e0e0;
}
.rp-calculator-header {
text-align: center;
margin-bottom: 30px;
}
.rp-calculator-header h2 {
color: #2c3e50;
margin: 0;
font-size: 28px;
}
.rp-calculator-header p {
color: #7f8c8d;
margin-top: 10px;
}
.rp-input-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
margin-bottom: 30px;
}
.rp-input-group {
display: flex;
flex-direction: column;
}
.rp-input-group label {
font-size: 14px;
font-weight: 600;
color: #34495e;
margin-bottom: 8px;
}
.rp-input-wrapper {
position: relative;
display: flex;
align-items: center;
}
.rp-input-symbol {
position: absolute;
left: 12px;
color: #7f8c8d;
font-weight: 500;
}
.rp-input-symbol.right {
left: auto;
right: 12px;
}
.rp-input-field {
width: 100%;
padding: 12px 12px 12px 30px;
border: 1px solid #bdc3c7;
border-radius: 6px;
font-size: 16px;
transition: border-color 0.3s;
}
.rp-input-field:focus {
outline: none;
border-color: #3498db;
box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.1);
}
.rp-input-field.percent {
padding-left: 12px;
padding-right: 30px;
}
.rp-btn-container {
grid-column: 1 / -1;
text-align: center;
margin-top: 10px;
}
.rp-calc-btn {
background-color: #27ae60;
color: white;
border: none;
padding: 15px 40px;
font-size: 18px;
font-weight: bold;
border-radius: 8px;
cursor: pointer;
transition: background-color 0.2s, transform 0.1s;
box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}
.rp-calc-btn:hover {
background-color: #219150;
}
.rp-calc-btn:active {
transform: translateY(2px);
}
.rp-results-section {
background-color: #f8f9fa;
border-radius: 8px;
padding: 25px;
border: 1px solid #e9ecef;
display: none;
}
.rp-results-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
}
.rp-result-card {
background: white;
padding: 15px;
border-radius: 6px;
border: 1px solid #e0e0e0;
text-align: center;
}
.rp-result-label {
font-size: 13px;
color: #7f8c8d;
text-transform: uppercase;
letter-spacing: 0.5px;
margin-bottom: 5px;
}
.rp-result-value {
font-size: 24px;
font-weight: 700;
color: #2c3e50;
}
.rp-result-value.positive {
color: #27ae60;
}
.rp-result-value.negative {
color: #c0392b;
}
.rp-content-section {
max-width: 800px;
margin: 40px auto;
line-height: 1.6;
color: #2c3e50;
}
.rp-content-section h2 {
margin-top: 30px;
color: #2c3e50;
}
.rp-content-section h3 {
color: #34495e;
}
.rp-content-section ul {
margin-bottom: 20px;
}
.rp-content-section li {
margin-bottom: 10px;
}
@media (max-width: 600px) {
.rp-input-grid, .rp-results-grid {
grid-template-columns: 1fr;
}
}
Investment Analysis
Cash on Cash Return
0.00%
Net Operating Income (NOI)
$0.00
function calculateRentalROI() {
// Get Input Values
var price = parseFloat(document.getElementById('rpPrice').value);
var downPayment = parseFloat(document.getElementById('rpDownPayment').value);
var interestRate = parseFloat(document.getElementById('rpInterestRate').value);
var termYears = parseFloat(document.getElementById('rpLoanTerm').value);
var monthlyRent = parseFloat(document.getElementById('rpMonthlyRent').value);
var annualTax = parseFloat(document.getElementById('rpPropTax').value);
var annualInsurance = parseFloat(document.getElementById('rpInsurance').value);
var monthlyHOA = parseFloat(document.getElementById('rpHOA').value);
var vacancyRate = parseFloat(document.getElementById('rpVacancy').value);
var closingCosts = parseFloat(document.getElementById('rpClosingCosts').value);
// Validation to prevent NaN errors
if (isNaN(price)) price = 0;
if (isNaN(downPayment)) downPayment = 0;
if (isNaN(interestRate)) interestRate = 0;
if (isNaN(termYears)) termYears = 30;
if (isNaN(monthlyRent)) monthlyRent = 0;
if (isNaN(annualTax)) annualTax = 0;
if (isNaN(annualInsurance)) annualInsurance = 0;
if (isNaN(monthlyHOA)) monthlyHOA = 0;
if (isNaN(vacancyRate)) vacancyRate = 0;
if (isNaN(closingCosts)) closingCosts = 0;
// 1. Calculate Mortgage Payment
var loanAmount = price – downPayment;
var monthlyInterest = interestRate / 100 / 12;
var numberOfPayments = termYears * 12;
var monthlyMortgage = 0;
if (interestRate === 0) {
monthlyMortgage = loanAmount / numberOfPayments;
} else {
monthlyMortgage = loanAmount * (monthlyInterest * Math.pow(1 + monthlyInterest, numberOfPayments)) / (Math.pow(1 + monthlyInterest, numberOfPayments) – 1);
}
if (isNaN(monthlyMortgage)) monthlyMortgage = 0;
// 2. Calculate Income
var grossAnnualIncome = monthlyRent * 12;
var vacancyLoss = grossAnnualIncome * (vacancyRate / 100);
var effectiveGrossIncome = grossAnnualIncome – vacancyLoss;
// 3. Calculate Operating Expenses (Excluding Mortgage)
var annualHOA = monthlyHOA * 12;
var totalOperatingExpenses = annualTax + annualInsurance + annualHOA;
// 4. Calculate Net Operating Income (NOI)
var noi = effectiveGrossIncome – totalOperatingExpenses;
// 5. Calculate Cash Flow
var annualDebtService = monthlyMortgage * 12;
var annualCashFlow = noi – annualDebtService;
var monthlyCashFlow = annualCashFlow / 12;
// 6. Calculate Returns
var totalCashInvested = downPayment + closingCosts;
var cashOnCashReturn = 0;
if (totalCashInvested > 0) {
cashOnCashReturn = (annualCashFlow / totalCashInvested) * 100;
}
var capRate = 0;
if (price > 0) {
capRate = (noi / price) * 100;
}
// Display Results
var cashFlowEl = document.getElementById('rpCashFlow');
cashFlowEl.innerText = "$" + monthlyCashFlow.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
if (monthlyCashFlow >= 0) {
cashFlowEl.className = "rp-result-value positive";
} else {
cashFlowEl.className = "rp-result-value negative";
}
document.getElementById('rpCoC').innerText = cashOnCashReturn.toFixed(2) + "%";
document.getElementById('rpCapRate').innerText = capRate.toFixed(2) + "%";
document.getElementById('rpNOI').innerText = "$" + noi.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
// Show result section
document.getElementById('rpResultSection').style.display = 'block';
}
Understanding Rental Property ROI
Investing in real estate is a numbers game. To ensure a property is a sound investment, you need to look beyond just the monthly rent. This Rental Property ROI Calculator helps investors analyze the four most critical metrics of property performance: Cash Flow, Cash-on-Cash Return, Cap Rate, and Net Operating Income (NOI).
1. Net Operating Income (NOI)
NOI is the foundation of real estate analysis. It represents the total income a property generates after all operating expenses are paid, but before the mortgage is paid. The formula is:
- NOI = (Gross Rental Income – Vacancy Losses) – Operating Expenses
Operating expenses include property taxes, insurance, maintenance, and HOA fees, but do not include your loan payments.
2. Cap Rate (Capitalization Rate)
The Cap Rate measures the natural rate of return on the property if it were purchased entirely with cash. It is the primary metric used to compare similar properties in the same market, regardless of financing.
- Cap Rate = (NOI / Purchase Price) × 100
A "good" cap rate varies by market, but generally, investors look for cap rates between 4% and 10% depending on the risk level and location.
3. Cash-on-Cash Return
This is arguably the most important metric for leveraged investors (those using a mortgage). It measures the return on the actual cash you invested (down payment + closing costs), rather than the total property price.
- Cash-on-Cash Return = (Annual Cash Flow / Total Cash Invested) × 100
For example, if you invest $50,000 cash to buy a $200,000 property and it generates $5,000 in positive cash flow per year, your Cash-on-Cash return is 10%.
4. Monthly Cash Flow
Cash flow is the profit remaining in your pocket after every single expense, including the mortgage, is paid. Positive cash flow ensures the property pays for itself and provides passive income. Negative cash flow means you are losing money every month to hold the asset.
How to Use This Calculator
To get the most accurate results, input realistic numbers for your expenses. Don't forget to account for Vacancy Rate (typically 5-8% depending on the area) and Maintenance (often estimated at 1% of the property value annually or 10% of rent).
By adjusting the "Down Payment" and "Loan Term," you can see how different financing structures affect your monthly cash flow and overall return on investment.