Analyze the profitability of your real estate investment instantly.
Income
Recurring Expenses (Monthly)
Variable Expenses (Estimates)
Gross Monthly Income:$0.00
Total Monthly Expenses:$0.00
Net Operating Income (NOI):$0.00
Monthly Cash Flow:$0.00
Annual Cash Flow:$0.00
function calculateCashFlow() {
// Get Inputs
var rent = parseFloat(document.getElementById('monthlyRent').value) || 0;
var otherIncome = parseFloat(document.getElementById('otherIncome').value) || 0;
var mortgage = parseFloat(document.getElementById('mortgagePayment').value) || 0;
var tax = parseFloat(document.getElementById('propertyTax').value) || 0;
var insurance = parseFloat(document.getElementById('insurance').value) || 0;
var hoa = parseFloat(document.getElementById('hoaFees').value) || 0;
var pmPercent = parseFloat(document.getElementById('pmFee').value) || 0;
var vacancyPercent = parseFloat(document.getElementById('vacancyRate').value) || 0;
var maintenancePercent = parseFloat(document.getElementById('maintenanceRate').value) || 0;
var capexPercent = parseFloat(document.getElementById('capexRate').value) || 0;
// Calculations
var grossIncome = rent + otherIncome;
// Calculate percentage based expenses based on RENT only (usually standard)
var vacancyCost = rent * (vacancyPercent / 100);
var maintenanceCost = rent * (maintenancePercent / 100);
var capexCost = rent * (capexPercent / 100);
var pmCost = rent * (pmPercent / 100);
var totalExpenses = tax + insurance + hoa + pmCost + vacancyCost + maintenanceCost + capexCost;
// Net Operating Income (NOI) = Income – Operating Expenses (excluding mortgage)
var noi = grossIncome – totalExpenses;
// Cash Flow = NOI – Mortgage
var monthlyCashFlow = noi – mortgage;
var annualCashFlow = monthlyCashFlow * 12;
// Display Results
var resultArea = document.getElementById('resultsArea');
resultArea.style.display = 'block';
document.getElementById('dispGrossIncome').innerText = formatCurrency(grossIncome);
document.getElementById('dispTotalExpenses').innerText = formatCurrency(totalExpenses + mortgage); // Displaying total cash outflow including mortgage for clarity
document.getElementById('dispNOI').innerText = formatCurrency(noi);
var cfElement = document.getElementById('dispMonthlyCashFlow');
cfElement.innerText = formatCurrency(monthlyCashFlow);
if (monthlyCashFlow < 0) {
cfElement.classList.add('negative');
cfElement.classList.remove('cash-flow-highlight');
} else {
cfElement.classList.remove('negative');
cfElement.classList.add('cash-flow-highlight');
}
document.getElementById('dispAnnualCashFlow').innerText = formatCurrency(annualCashFlow);
}
function formatCurrency(num) {
return '$' + num.toFixed(2).replace(/\d(?=(\d{3})+\.)/g, '$&,');
}
Understanding Rental Property Cash Flow
Cash flow is the lifeblood of any rental property investment. Simply put, it is the money left over after all expenses have been paid. A positive cash flow indicates that your investment is generating profit every month, while negative cash flow means the property is costing you money to hold.
Using a Rental Property Cash Flow Calculator helps investors move beyond "napkin math" to ensure they account for hidden costs like vacancy, repairs, and capital expenditures (CapEx).
Gross Rental Income: The total amount of rent collected from tenants.
Vacancy Rate: No property is occupied 100% of the time. A standard conservative estimate is 5% to 8% (roughly one month vacant per year).
CapEx (Capital Expenditures): This is a savings fund for big-ticket items that will eventually need replacing, such as the roof, HVAC, or water heater.
Net Operating Income (NOI): This is your profitability before paying the mortgage. Lenders look at this number closely.
Is Your Investment a Good Deal?
While every investor has different goals, a common benchmark for residential real estate is to aim for at least $100 to $200 per door in monthly positive cash flow. Additionally, investors look at the Cash on Cash Return, which compares the annual cash flow to the total cash invested (down payment + closing costs + rehab).
Remember, cash flow isn't the only way to win in real estate—appreciation, loan paydown, and tax benefits also play a role—but cash flow is what keeps you in business during market downturns.
Frequently Asked Questions
Should I include property management fees if I manage it myself?
Yes. You should always account for property management (typically 8-10%) in your calculations. This ensures the deal still works if you decide to hire a manager later, and it compensates you for your time.
What is the 50% Rule?
The 50% rule is a quick screening heuristic suggesting that operating expenses (excluding mortgage) will consume roughly 50% of your gross rental income. While useful for quick estimates, this calculator provides a much more accurate detailed analysis.