Analyze the profitability of your real estate investment.
Purchase & Loan Details
Income & Expenses
Loan Amount:
Monthly Principal & Interest:
Total Monthly Expenses:
Net Operating Income (Monthly):
Estimated Monthly Cash Flow
Cash on Cash Return:
function calculateRentalCashFlow() {
// 1. Get Input Values
var price = parseFloat(document.getElementById('rp_price').value);
var downPercent = parseFloat(document.getElementById('rp_down').value);
var interestRate = parseFloat(document.getElementById('rp_interest').value);
var years = parseFloat(document.getElementById('rp_term').value);
var rent = parseFloat(document.getElementById('rp_rent').value);
var taxIns = parseFloat(document.getElementById('rp_tax_ins').value);
var hoa = parseFloat(document.getElementById('rp_hoa').value);
var repairRate = parseFloat(document.getElementById('rp_repair').value);
// 2. Validation
if (isNaN(price) || isNaN(downPercent) || isNaN(interestRate) || isNaN(years) || isNaN(rent) || isNaN(taxIns)) {
alert("Please fill in all required fields with valid numbers.");
return;
}
// Handle defaults for optional fields if empty
if (isNaN(hoa)) hoa = 0;
if (isNaN(repairRate)) repairRate = 0;
// 3. Calculation Logic
// Loan Calculations
var downPaymentAmount = price * (downPercent / 100);
var loanAmount = price – downPaymentAmount;
var monthlyRate = (interestRate / 100) / 12;
var totalPayments = years * 12;
// Mortgage P&I Calculation
var monthlyPI = 0;
if (interestRate === 0) {
monthlyPI = loanAmount / totalPayments;
} else {
monthlyPI = (loanAmount * monthlyRate) / (1 – Math.pow(1 + monthlyRate, -totalPayments));
}
// Expenses Calculations
var maintenanceVacancyCost = rent * (repairRate / 100);
var totalMonthlyExpenses = monthlyPI + taxIns + hoa + maintenanceVacancyCost;
// Cash Flow Calculations
var monthlyCashFlow = rent – totalMonthlyExpenses;
var annualCashFlow = monthlyCashFlow * 12;
var noi = (rent * 12) – ((taxIns + hoa + maintenanceVacancyCost) * 12);
// Cash on Cash Return = Annual Cash Flow / Total Cash Invested (Downpayment)
// Note: Simplified CoC (ignoring closing costs for simplicity unless asked)
var cocReturn = 0;
if (downPaymentAmount > 0) {
cocReturn = (annualCashFlow / downPaymentAmount) * 100;
}
// 4. Display Results
var resultDiv = document.getElementById('rp_results');
resultDiv.style.display = 'block';
// Format Currency Function
function formatMoney(num) {
return "$" + num.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
}
document.getElementById('res_loan').innerHTML = formatMoney(loanAmount);
document.getElementById('res_pi').innerHTML = formatMoney(monthlyPI);
document.getElementById('res_expenses').innerHTML = formatMoney(totalMonthlyExpenses);
document.getElementById('res_noi').innerHTML = formatMoney(rent – (taxIns + hoa + maintenanceVacancyCost)); // Monthly NOI (Rent – OpEx excluding debt)
var cfElement = document.getElementById('res_cashflow');
cfElement.innerHTML = formatMoney(monthlyCashFlow);
// Styling for positive/negative cash flow
if (monthlyCashFlow >= 0) {
cfElement.className = "rp-cashflow-amount";
cfElement.style.color = "#27ae60";
} else {
cfElement.className = "rp-cashflow-amount rp-negative";
cfElement.style.color = "#c0392b";
}
document.getElementById('res_coc').innerHTML = cocReturn.toFixed(2) + "%";
}
Understanding Rental Property Cash Flow
Calculating cash flow is the single most important step in analyzing a rental property investment. Cash flow represents the net amount of money moving in or out of your business every month after all expenses have been paid. Positive cash flow means the property generates income, while negative cash flow means you are losing money to hold the asset.
How to Use This Calculator
This Rental Property Cash Flow Calculator is designed to provide a comprehensive financial snapshot of a potential real estate deal. Here is how to interpret the inputs:
Purchase Price & Loan: Enter the agreed purchase price and your financing terms. The calculator automatically determines your monthly mortgage payment (Principal & Interest).
Rental Income: Be realistic with your projected rent. Research comparable properties in the area (comps) to find an accurate number.
Expenses (Taxes, Insurance, HOA): These are fixed recurring costs. Do not ignore HOA fees if the property is in a managed community.
Repair/Vacancy Reserve: Experienced investors set aside a percentage of rent (typically 5-15%) to cover future repairs and months where the property sits empty.
Key Metrics Defined
Net Operating Income (NOI): This is the profitability of the property before factoring in the mortgage. It is calculated as Total Income minus Operating Expenses. Lenders often look at this metric to determine the property's value.
Cash on Cash Return (CoC): This percentage tells you how hard your money is working. It compares your annual cash flow to the actual cash you invested (your down payment). A higher percentage generally indicates a better return on investment compared to alternative vehicles like stocks or bonds.
Why is my Cash Flow Negative?
If the result turns red, your expenses exceed your rental income. This often happens if the purchase price is too high relative to rents, the interest rate is high, or you have not made a large enough down payment to lower the mortgage service. To fix this, you may need to negotiate a lower price, increase the down payment, or look for a property with better rental yield potential.