.rpc-grid { display: flex; flex-wrap: wrap; gap: 20px; }
.rpc-col { flex: 1; min-width: 300px; }
.rpc-input-group { margin-bottom: 15px; }
.rpc-label { display: block; margin-bottom: 5px; font-weight: 600; color: #333; font-size: 14px; }
.rpc-input { width: 100%; padding: 10px; border: 1px solid #ccc; border-radius: 4px; font-size: 16px; box-sizing: border-box; }
.rpc-input:focus { border-color: #007bff; outline: none; box-shadow: 0 0 0 2px rgba(0,123,255,0.25); }
.rpc-btn { display: block; width: 100%; padding: 12px; background-color: #28a745; color: white; border: none; border-radius: 4px; font-size: 18px; font-weight: bold; cursor: pointer; transition: background 0.3s; margin-top: 10px; }
.rpc-btn:hover { background-color: #218838; }
.rpc-result-card { background: #f8f9fa; padding: 20px; border-radius: 8px; border-left: 5px solid #007bff; margin-top: 20px; }
.rpc-result-row { display: flex; justify-content: space-between; margin-bottom: 10px; border-bottom: 1px solid #e9ecef; padding-bottom: 5px; }
.rpc-result-row:last-child { border-bottom: none; }
.rpc-result-label { color: #555; }
.rpc-result-value { font-weight: bold; color: #222; }
.rpc-big-result { text-align: center; margin-bottom: 20px; }
.rpc-big-result .val { font-size: 32px; font-weight: 800; color: #28a745; display: block; }
.rpc-big-result .lbl { font-size: 14px; color: #666; text-transform: uppercase; letter-spacing: 1px; }
.rpc-article { margin-top: 40px; line-height: 1.6; color: #444; }
.rpc-article h2 { color: #222; border-bottom: 2px solid #eee; padding-bottom: 10px; }
.rpc-article h3 { color: #333; margin-top: 20px; }
.rpc-error { color: #dc3545; display: none; margin-top: 10px; font-weight: bold; text-align: center; }
function calculateCashFlow() {
// Get inputs by ID
var price = parseFloat(document.getElementById('rpc_price').value);
var rent = parseFloat(document.getElementById('rpc_rent').value);
var downPct = parseFloat(document.getElementById('rpc_down').value);
var rate = parseFloat(document.getElementById('rpc_rate').value);
var term = parseFloat(document.getElementById('rpc_term').value);
var closing = parseFloat(document.getElementById('rpc_closing').value);
var taxYear = parseFloat(document.getElementById('rpc_tax').value);
var insuranceYear = parseFloat(document.getElementById('rpc_insurance').value);
var hoaMonth = parseFloat(document.getElementById('rpc_hoa').value);
var maintPct = parseFloat(document.getElementById('rpc_maint').value);
var pmPct = parseFloat(document.getElementById('rpc_pm').value);
// Validation
if (isNaN(price) || isNaN(rent) || isNaN(downPct) || isNaN(rate) || isNaN(term)) {
document.getElementById('rpc-error').style.display = 'block';
document.getElementById('rpc-results').style.display = 'none';
return;
}
document.getElementById('rpc-error').style.display = 'none';
// 1. Calculate Mortgage (Principal & Interest)
var downPayment = price * (downPct / 100);
var loanAmount = price – downPayment;
var monthlyRate = (rate / 100) / 12;
var numPayments = term * 12;
var mortgagePayment = 0;
if (rate > 0) {
mortgagePayment = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, numPayments)) / (Math.pow(1 + monthlyRate, numPayments) – 1);
} else {
mortgagePayment = loanAmount / numPayments;
}
// 2. Calculate Monthly Expenses
var monthlyTax = taxYear / 12;
var monthlyInsurance = insuranceYear / 12;
var monthlyMaint = rent * (maintPct / 100);
var monthlyPM = rent * (pmPct / 100);
var totalOperatingExpenses = monthlyTax + monthlyInsurance + hoaMonth + monthlyMaint + monthlyPM;
var totalMonthlyExpenses = totalOperatingExpenses + mortgagePayment;
// 3. Calculate Key Metrics
var monthlyCashFlow = rent – totalMonthlyExpenses;
var annualCashFlow = monthlyCashFlow * 12;
var totalInvested = downPayment + closing;
var cashOnCash = 0;
if (totalInvested > 0) {
cashOnCash = (annualCashFlow / totalInvested) * 100;
}
// NOI calculation (Annual)
var annualNOI = (rent * 12) – (totalOperatingExpenses * 12);
var capRate = (annualNOI / price) * 100;
// 4. Update UI
document.getElementById('rpc-results').style.display = 'block';
// Formatters
var currencyFmt = new Intl.NumberFormat('en-US', { style: 'currency', currency: 'USD' });
var pctFmt = new Intl.NumberFormat('en-US', { style: 'decimal', minimumFractionDigits: 2, maximumFractionDigits: 2 });
document.getElementById('res_cashflow').innerHTML = currencyFmt.format(monthlyCashFlow);
document.getElementById('res_cashflow').style.color = monthlyCashFlow >= 0 ? '#28a745' : '#dc3545';
document.getElementById('res_coc').innerHTML = pctFmt.format(cashOnCash) + "%";
document.getElementById('res_coc').style.color = cashOnCash >= 8 ? '#28a745' : (cashOnCash > 0 ? '#007bff' : '#dc3545');
document.getElementById('res_noi').innerHTML = currencyFmt.format(annualNOI) + " / yr";
document.getElementById('res_cap').innerHTML = pctFmt.format(capRate) + "%";
document.getElementById('res_expenses').innerHTML = currencyFmt.format(totalMonthlyExpenses);
document.getElementById('res_mortgage').innerHTML = currencyFmt.format(mortgagePayment);
document.getElementById('res_invested').innerHTML = currencyFmt.format(totalInvested);
}
Rental Property Cash Flow Calculator
Property Details
Financing
Annual Expenses
Recommended: 10-15%
Please fill out all fields with valid numbers.
$0.00
Monthly Cash Flow
0.00%
Cash on Cash Return
Net Operating Income (NOI)
$0.00 / yr
Cap Rate
0.00%
Total Monthly Expenses
$0.00
Monthly Mortgage Payment (P&I)
$0.00
Total Cash Invested
$0.00
Understanding Your Rental Property Investment
Investing in real estate is one of the most reliable ways to build wealth, but simply buying a property doesn't guarantee profit. Successful investors rely on accurate math to determine if a property is an asset or a liability. This Rental Property Cash Flow Calculator breaks down the essential metrics you need to evaluate a potential deal.
What is Cash on Cash Return (CoC)?
Cash on Cash Return is often considered the most important metric for rental investors. Unlike standard ROI, CoC measures the annual return specifically on the cash you actually invested (down payment + closing costs), rather than the total price of the home. A CoC return of 8-12% is typically considered a solid benchmark for a rental property, beating the historical average of the stock market.
Net Operating Income (NOI) vs. Cash Flow
It is crucial to distinguish between NOI and Cash Flow:
- Net Operating Income (NOI): This is your total revenue minus operating expenses (taxes, insurance, maintenance), excluding mortgage payments. It measures the property's profitability purely as an asset.
- Cash Flow: This is what ends up in your pocket after paying the mortgage debt service. Positive cash flow is essential for long-term sustainability and scaling your portfolio.
The 1% Rule and 50% Rule
While this calculator provides exact figures, investors often use quick rules of thumb for screening:
- The 1% Rule: Monthly rent should be at least 1% of the purchase price. (e.g., A $200,000 home should rent for $2,000/month).
- The 50% Rule: Estimate that 50% of your gross rent will go toward operating expenses (excluding mortgage). If the remaining 50% covers the mortgage with room to spare, it may be a good deal.
Use the results above to validate your assumptions and ensure your investment meets your financial goals before making an offer.