.rpc-header { text-align: center; margin-bottom: 30px; }
.rpc-header h2 { color: #2c3e50; margin-bottom: 10px; font-size: 28px; }
.rpc-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
@media (max-width: 768px) { .rpc-grid { grid-template-columns: 1fr; } }
.rpc-section { background: #f8f9fa; padding: 20px; border-radius: 6px; border: 1px solid #e9ecef; }
.rpc-section h3 { margin-top: 0; color: #34495e; font-size: 18px; border-bottom: 2px solid #3498db; padding-bottom: 10px; margin-bottom: 15px; }
.rpc-input-group { margin-bottom: 15px; }
.rpc-input-group label { display: block; margin-bottom: 5px; font-weight: 600; font-size: 14px; color: #555; }
.rpc-input-group input { width: 100%; padding: 10px; border: 1px solid #ccc; border-radius: 4px; font-size: 16px; box-sizing: border-box; transition: border-color 0.3s; }
.rpc-input-group input:focus { border-color: #3498db; outline: none; }
.rpc-btn { width: 100%; padding: 15px; background-color: #2ecc71; color: white; border: none; border-radius: 5px; font-size: 18px; font-weight: bold; cursor: pointer; margin-top: 20px; transition: background-color 0.3s; }
.rpc-btn:hover { background-color: #27ae60; }
.rpc-results { margin-top: 30px; background: #2c3e50; color: white; padding: 25px; border-radius: 8px; }
.rpc-result-row { display: flex; justify-content: space-between; padding: 10px 0; border-bottom: 1px solid rgba(255,255,255,0.1); }
.rpc-result-row:last-child { border-bottom: none; }
.rpc-result-value { font-weight: bold; font-size: 18px; }
.rpc-highlight { color: #2ecc71; font-size: 24px; }
.rpc-highlight-neg { color: #e74c3c; font-size: 24px; }
.rpc-content { margin-top: 40px; line-height: 1.6; color: #333; }
.rpc-content h2 { color: #2c3e50; margin-top: 30px; }
.rpc-content ul { padding-left: 20px; }
.rpc-content li { margin-bottom: 10px; }
.rpc-tooltip { font-size: 12px; color: #7f8c8d; margin-top: 2px; }
function calculateRentalROI() {
// 1. Get Inputs
var price = parseFloat(document.getElementById('rpc-price').value) || 0;
var downPercent = parseFloat(document.getElementById('rpc-down').value) || 0;
var rate = parseFloat(document.getElementById('rpc-rate').value) || 0;
var term = parseFloat(document.getElementById('rpc-term').value) || 0;
var closingCosts = parseFloat(document.getElementById('rpc-closing').value) || 0;
var rent = parseFloat(document.getElementById('rpc-rent').value) || 0;
var taxAnnual = parseFloat(document.getElementById('rpc-tax').value) || 0;
var insAnnual = parseFloat(document.getElementById('rpc-insurance').value) || 0;
var hoa = parseFloat(document.getElementById('rpc-hoa').value) || 0;
var vacancyRate = parseFloat(document.getElementById('rpc-vacancy').value) || 0;
var maintRate = parseFloat(document.getElementById('rpc-maintenance').value) || 0;
var mgmtRate = parseFloat(document.getElementById('rpc-management').value) || 0;
// 2. Calculate Mortgage (P&I)
var downPayment = price * (downPercent / 100);
var loanAmount = price – downPayment;
var monthlyRate = (rate / 100) / 12;
var numPayments = term * 12;
var mortgagePayment = 0;
if (loanAmount > 0 && rate > 0) {
mortgagePayment = (loanAmount * monthlyRate) / (1 – Math.pow(1 + monthlyRate, -numPayments));
} else if (loanAmount > 0 && rate === 0) {
mortgagePayment = loanAmount / numPayments;
}
// 3. Calculate Monthly Expenses
var monthlyTax = taxAnnual / 12;
var monthlyIns = insAnnual / 12;
var vacancyCost = rent * (vacancyRate / 100);
var maintCost = rent * (maintRate / 100);
var mgmtCost = rent * (mgmtRate / 100);
// Operating Expenses (Expenses excluding financing) for NOI
var monthlyOperatingExpenses = monthlyTax + monthlyIns + hoa + vacancyCost + maintCost + mgmtCost;
// Total Monthly Expenses (Operating + Debt Service)
var totalMonthlyExpenses = monthlyOperatingExpenses + mortgagePayment;
// 4. Calculate Cash Flow
var monthlyCashFlow = rent – totalMonthlyExpenses;
var annualCashFlow = monthlyCashFlow * 12;
// 5. Calculate Metrics
var annualNOI = (rent * 12) – (monthlyOperatingExpenses * 12);
var totalInvested = downPayment + closingCosts;
var cocReturn = 0;
if (totalInvested > 0) {
cocReturn = (annualCashFlow / totalInvested) * 100;
}
var capRate = 0;
if (price > 0) {
capRate = (annualNOI / price) * 100;
}
// 6. formatting functions
var fmtMoney = new Intl.NumberFormat('en-US', { style: 'currency', currency: 'USD' });
var fmtPct = new Intl.NumberFormat('en-US', { style: 'percent', minimumFractionDigits: 2, maximumFractionDigits: 2 });
// 7. Display Results
document.getElementById('rpc-res-cashflow').innerHTML = fmtMoney.format(monthlyCashFlow);
document.getElementById('rpc-res-coc').innerHTML = cocReturn.toFixed(2) + '%';
document.getElementById('rpc-res-cap').innerHTML = capRate.toFixed(2) + '%';
document.getElementById('rpc-res-mortgage').innerHTML = fmtMoney.format(mortgagePayment);
document.getElementById('rpc-res-expenses').innerHTML = fmtMoney.format(totalMonthlyExpenses);
document.getElementById('rpc-res-noi').innerHTML = fmtMoney.format(annualNOI);
document.getElementById('rpc-res-invested').innerHTML = fmtMoney.format(totalInvested);
// Styling positive/negative
var cfElement = document.getElementById('rpc-res-cashflow');
if(monthlyCashFlow >= 0) {
cfElement.className = "rpc-result-value rpc-highlight";
} else {
cfElement.className = "rpc-result-value rpc-highlight-neg";
}
document.getElementById('rpc-result-container').style.display = 'block';
// Scroll to results on mobile
if(window.innerWidth < 768) {
document.getElementById('rpc-result-container').scrollIntoView({behavior: 'smooth'});
}
}
Rental Property Cash Flow Calculator
Analyze the potential ROI, Cap Rate, and Monthly Cash Flow of your real estate investment.
Purchase & Loan Details
Estimated upfront fees outside down payment.
Income & Operating Expenses
Investment Analysis
Net Monthly Cash Flow:
Cash on Cash Return (ROI):
Cap Rate:
Monthly Principal & Interest:
Total Monthly Expenses:
Net Operating Income (Annual):
Total Cash Invested:
Understanding Rental Property Cash Flow
Investing in real estate is a numbers game. Unlike buying a primary residence where emotion plays a large role, a rental property must make mathematical sense. This Rental Property Cash Flow Calculator helps investors determine if a property will generate income (positive cash flow) or cost money to hold (negative cash flow).
Key Real Estate Metrics Explained
1. Cash Flow
Cash flow is the profit you bring in each month after all expenses are paid. It is calculated as:
Gross Rental Income – (Mortgage + Taxes + Insurance + HOA + Vacancy + Repairs + Management)
Positive cash flow ensures the property pays for itself and provides you with passive income.
2. Cash on Cash Return (CoC ROI)
This is arguably the most important metric for investors. It measures the return on the actual cash you invested (down payment + closing costs), not the total property value. It allows you to compare real estate returns against stocks or other investments.
Formula: (Annual Pre-Tax Cash Flow / Total Cash Invested) × 100
A "good" CoC return varies by market, but many investors aim for 8-12%.
3. Cap Rate (Capitalization Rate)
The Cap Rate measures the property's natural rate of return assuming you paid all cash (no mortgage). It is useful for comparing the profitability of different properties regardless of how they are financed.
Formula: (Net Operating Income / Purchase Price) × 100
Common Expense Pitfalls
New investors often overestimate profit by ignoring "hidden" expenses. This calculator includes inputs for these critical factors:
- Vacancy Rate: Properties won't be rented 365 days a year. A 5-8% vacancy allowance is standard.
- Maintenance & CapEx: Roofs leak and toilets break. Setting aside 5-10% of rent for repairs is essential for long-term safety.
- Property Management: If you don't plan to be a landlord answering calls at midnight, account for 8-10% for professional management.