Analyze the profitability of your real estate investment instantly.
Monthly Mortgage (P&I):$0.00
Net Operating Income (Monthly):$0.00
Est. Monthly Cash Flow:$0.00
Cap Rate:0.00%
Cash on Cash Return:0.00%
Understanding Your Rental Property Analysis
Investing in real estate requires precise calculations to ensure a positive return on investment (ROI). This Rental Property Cash Flow Calculator helps investors determine if a property will generate income or drain resources. By inputting the purchase price, financing terms, and operating data, you can visualize the financial health of a potential deal.
Key Metrics Explained
Monthly Cash Flow: This is your profit after all expenses and mortgage payments are made. A positive number indicates the property pays for itself and generates income. Formula: (Rent Income) – (Operating Expenses) – (Mortgage Payment)
Net Operating Income (NOI): This metric looks at the profitability of the property excluding financing costs. It is crucial for calculating the Cap Rate. Formula: (Annual Rent) – (Annual Operating Expenses)
Cap Rate (Capitalization Rate): A standard measure used to compare different real estate investments. It represents the potential return on an investment assuming it was paid for in all cash. Higher percentages generally indicate better returns (but often higher risk). Formula: (Annual NOI / Purchase Price) × 100
Cash on Cash Return: This measures the annual return on the actual cash you invested (down payment + closing costs), rather than the total loan amount. It tells you how hard your specific dollars are working. Formula: (Annual Pre-Tax Cash Flow / Total Cash Invested) × 100
How to Use This Calculator
To get the most accurate results, ensure you include all monthly expenses in the "Total Monthly Expenses" field. This should include:
Property Taxes (monthly portion)
Landlord Insurance
Property Management Fees (typically 8-10% of rent)
Maintenance and Repairs Budget (typically 5-10% of rent)
Vacancy Reserve (typically 5% of rent)
HOA Fees (if applicable)
function calculateRentalROI() {
// 1. Get Input Values
var price = parseFloat(document.getElementById('rpc_price').value);
var downPercent = parseFloat(document.getElementById('rpc_down').value);
var interestRate = parseFloat(document.getElementById('rpc_rate').value);
var termYears = parseFloat(document.getElementById('rpc_term').value);
var rent = parseFloat(document.getElementById('rpc_rent').value);
var expenses = parseFloat(document.getElementById('rpc_expenses').value);
// 2. Validation
if (isNaN(price) || isNaN(downPercent) || isNaN(interestRate) || isNaN(termYears) || isNaN(rent) || isNaN(expenses)) {
alert("Please fill in all fields with valid numbers.");
return;
}
// 3. Loan Calculations
var downPaymentAmount = price * (downPercent / 100);
var loanAmount = price – downPaymentAmount;
// Monthly Mortgage Calculation (M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ])
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);
}
// 4. ROI Calculations
// NOI (Monthly) = Rent – Operating Expenses (Not including mortgage)
var monthlyNOI = rent – expenses;
var annualNOI = monthlyNOI * 12;
// Cash Flow = NOI – Mortgage
var monthlyCashFlow = monthlyNOI – monthlyMortgage;
var annualCashFlow = monthlyCashFlow * 12;
// Cap Rate = (Annual NOI / Purchase Price) * 100
var capRate = (annualNOI / price) * 100;
// Cash on Cash Return = (Annual Cash Flow / Total Cash Invested) * 100
// Note: Total Cash Invested is Down Payment. (Closing costs ignored for this simplified calc)
var cashOnCash = 0;
if (downPaymentAmount > 0) {
cashOnCash = (annualCashFlow / downPaymentAmount) * 100;
} else {
// If 0 down, Cash on Cash is infinite mathematically, but we check logic
cashOnCash = 0;
}
// 5. Update UI
var resultsDiv = document.getElementById('rpc_results');
resultsDiv.style.display = 'block';
document.getElementById('res_mortgage').innerText = "$" + monthlyMortgage.toFixed(2);
document.getElementById('res_noi').innerText = "$" + monthlyNOI.toFixed(2);
var cfElement = document.getElementById('res_cashflow');
cfElement.innerText = "$" + monthlyCashFlow.toFixed(2);
// Style Cash Flow color based on profitability
if (monthlyCashFlow >= 0) {
cfElement.classList.remove('rpc-negative');
cfElement.classList.add('rpc-highlight');
} else {
cfElement.classList.remove('rpc-highlight');
cfElement.classList.add('rpc-negative');
}
document.getElementById('res_caprate').innerText = capRate.toFixed(2) + "%";
document.getElementById('res_coc').innerText = cashOnCash.toFixed(2) + "%";
}