.rp-calculator-container {
font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
max-width: 800px;
margin: 0 auto;
padding: 20px;
background: #f9f9f9;
border: 1px solid #e0e0e0;
border-radius: 8px;
}
.rp-calc-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
}
@media (max-width: 768px) {
.rp-calc-grid {
grid-template-columns: 1fr;
}
}
.rp-input-group {
margin-bottom: 15px;
}
.rp-input-group label {
display: block;
font-weight: 600;
margin-bottom: 5px;
color: #333;
font-size: 14px;
}
.rp-input-group input, .rp-input-group select {
width: 100%;
padding: 10px;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
.rp-section-title {
grid-column: 1 / -1;
font-size: 18px;
color: #2c3e50;
border-bottom: 2px solid #3498db;
padding-bottom: 5px;
margin-top: 10px;
margin-bottom: 15px;
}
.rp-btn {
grid-column: 1 / -1;
background-color: #2ecc71;
color: white;
padding: 15px;
border: none;
border-radius: 5px;
font-size: 18px;
cursor: pointer;
font-weight: bold;
transition: background 0.3s;
text-align: center;
}
.rp-btn:hover {
background-color: #27ae60;
}
.rp-results {
grid-column: 1 / -1;
background: #fff;
padding: 20px;
border-radius: 5px;
margin-top: 20px;
border: 1px solid #ddd;
display: none;
}
.rp-result-row {
display: flex;
justify-content: space-between;
padding: 10px 0;
border-bottom: 1px solid #eee;
}
.rp-result-row:last-child {
border-bottom: none;
}
.rp-result-value {
font-weight: bold;
color: #2c3e50;
}
.rp-highlight {
color: #27ae60;
font-size: 1.2em;
}
.rp-error {
color: #c0392b;
font-weight: bold;
}
.seo-content {
max-width: 800px;
margin: 40px auto;
font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
line-height: 1.6;
color: #444;
}
.seo-content h2 {
color: #2c3e50;
margin-top: 30px;
}
.seo-content p {
margin-bottom: 15px;
}
.seo-content ul {
margin-bottom: 15px;
padding-left: 20px;
}
.seo-content li {
margin-bottom: 8px;
}
Why Use a Rental Property Calculator?
Investing in real estate is one of the most reliable ways to build wealth, but it requires precise mathematical analysis to ensure profitability. This Rental Property Cash Flow & ROI Calculator helps investors analyze the potential returns of a real estate investment by accounting for all income sources and operating expenses.
Whether you are evaluating a single-family home, a duplex, or a condo, understanding your numbers is crucial to avoiding bad investments that drain your capital rather than growing it.
Key Metrics Explained
Cash Flow
Cash flow is the profit you bring in each month after all expenses, including the mortgage, are paid. A positive cash flow indicates a healthy investment that generates passive income. Our calculator deducts vacancy rates, maintenance costs, taxes, insurance, and management fees from your gross rent to give you a realistic "net" figure.
Cash on Cash Return (CoC)
Cash on Cash Return measures the annual pre-tax cash flow relative to the total amount of cash invested. This is a critical metric because it tells you how hard your actual money is working for you. It is calculated using the formula:
- CoC ROI = (Annual Cash Flow / Total Cash Invested) x 100%
The "Total Cash Invested" includes your down payment, closing costs, and any immediate repair costs.
Cap Rate (Capitalization Rate)
The Cap Rate measures the property's natural rate of return, independent of debt financing. It is calculated by dividing the Net Operating Income (NOI) by the purchase price. Cap Rate is excellent for comparing multiple properties against each other to see which has better intrinsic value, regardless of how you finance them.
Net Operating Income (NOI)
NOI is the total income the property generates minus all necessary operating expenses. Note that NOI does not include mortgage payments (principal and interest). Lenders often look at NOI to determine if a property generates enough income to cover the debt service.
How to Maximize Your Rental Returns
To improve the results shown in the calculator, investors can focus on two main levers: increasing income or decreasing expenses.
- Increase Rent: Strategic renovations can allow you to charge higher premiums.
- Reduce Vacancy: Screening for long-term tenants reduces turnover costs.
- Refinance: Lowering your interest rate reduces your monthly mortgage payment, directly increasing cash flow.
function calculateRentalMetrics() {
// 1. Get Inputs
var price = parseFloat(document.getElementById('rp_purchase_price').value) || 0;
var closingCosts = parseFloat(document.getElementById('rp_closing_costs').value) || 0;
var downPaymentPercent = parseFloat(document.getElementById('rp_down_payment_percent').value) || 0;
var interestRate = parseFloat(document.getElementById('rp_interest_rate').value) || 0;
var termYears = parseFloat(document.getElementById('rp_loan_term').value) || 30;
var monthlyRent = parseFloat(document.getElementById('rp_monthly_rent').value) || 0;
var vacancyRate = parseFloat(document.getElementById('rp_vacancy_rate').value) || 0;
var annualTax = parseFloat(document.getElementById('rp_property_tax').value) || 0;
var annualInsurance = parseFloat(document.getElementById('rp_insurance').value) || 0;
var monthlyHOA = parseFloat(document.getElementById('rp_hoa').value) || 0;
var annualMaintenance = parseFloat(document.getElementById('rp_maintenance').value) || 0;
var mgmtFeePercent = parseFloat(document.getElementById('rp_management_fee').value) || 0;
// 2. Calculate Mortgage (P&I)
var downPaymentAmount = price * (downPaymentPercent / 100);
var loanAmount = price – downPaymentAmount;
var monthlyRate = (interestRate / 100) / 12;
var numberOfPayments = termYears * 12;
var monthlyMortgage = 0;
if (loanAmount > 0 && interestRate > 0) {
monthlyMortgage = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, numberOfPayments)) / (Math.pow(1 + monthlyRate, numberOfPayments) – 1);
} else if (loanAmount > 0 && interestRate === 0) {
monthlyMortgage = loanAmount / numberOfPayments;
}
// 3. Calculate Income
var annualGrossRent = monthlyRent * 12;
var vacancyLoss = annualGrossRent * (vacancyRate / 100);
var effectiveGrossIncome = annualGrossRent – vacancyLoss;
// 4. Calculate Operating Expenses
var annualMgmtFee = effectiveGrossIncome * (mgmtFeePercent / 100);
var totalAnnualExpenses = annualTax + annualInsurance + (monthlyHOA * 12) + annualMaintenance + annualMgmtFee;
var totalMonthlyExpenses = totalAnnualExpenses / 12;
// 5. Calculate Metrics
var annualNOI = effectiveGrossIncome – totalAnnualExpenses; // Net Operating Income
var annualDebtService = monthlyMortgage * 12;
var annualCashFlow = annualNOI – annualDebtService;
var monthlyCashFlow = annualCashFlow / 12;
var totalCashInvested = downPaymentAmount + closingCosts;
var cashOnCashReturn = 0;
if (totalCashInvested > 0) {
cashOnCashReturn = (annualCashFlow / totalCashInvested) * 100;
}
var capRate = 0;
if (price > 0) {
capRate = (annualNOI / price) * 100;
}
// 6. Format Display
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
});
document.getElementById('rp_monthly_cashflow').innerText = formatter.format(monthlyCashFlow);
document.getElementById('rp_coc_return').innerText = cashOnCashReturn.toFixed(2) + "%";
document.getElementById('rp_cap_rate').innerText = capRate.toFixed(2) + "%";
document.getElementById('rp_noi').innerText = formatter.format(annualNOI);
document.getElementById('rp_total_investment').innerText = formatter.format(totalCashInvested);
document.getElementById('rp_mortgage_payment').innerText = formatter.format(monthlyMortgage);
// Color coding for Cash Flow
var cashFlowEl = document.getElementById('rp_monthly_cashflow');
if(monthlyCashFlow < 0) {
cashFlowEl.style.color = '#c0392b'; // Red for negative
} else {
cashFlowEl.style.color = '#27ae60'; // Green for positive
}
// Show Results
document.getElementById('rp_result_container').style.display = 'block';
}