Analyze your real estate investment performance instantly.
Monthly Income
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$
Fixed Monthly Expenses
$
$
$
Variable Expenses (Estimates)
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%
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Total Monthly Income:$0.00
Operating Expenses:$0.00
Net Operating Income (NOI):$0.00
Monthly Cash Flow:$0.00
Understanding Rental Property Cash Flow
Cash flow is the lifeblood of any real estate investment. It represents the net amount of cash moving in or out of a rental property business after all expenses have been paid. A positive cash flow indicates that the property is generating income, while a negative cash flow means the property is costing you money to maintain.
Why Accurate Cash Flow Calculation Matters
Many new investors make the mistake of only calculating the mortgage against the rent. However, successful real estate investing requires accounting for both fixed and variable costs.
Vacancy Rate: Properties won't be occupied 365 days a year. A standard conservative estimate is 5-8% to account for turnover periods.
Repairs & CapEx: Roofs leak and water heaters break. Setting aside 5-10% of monthly rent ensures you have funds when big ticket items need replacement.
Property Management: Even if you manage it yourself, your time has value. Factoring in 8-10% helps you see if the deal still works if you eventually hire a professional.
How to Use This Calculator
To get the most accurate result from our Rental Property Cash Flow Calculator, input your expected Gross Monthly Rent based on comparable properties in the area. Be honest about your expenses. Underestimating taxes, insurance, or maintenance is the fastest way to turn a profitable deal into a financial burden.
The Net Operating Income (NOI) displayed in the results is a critical metric used by lenders and investors to determine the profitability of a real estate asset, independent of the financing method.
function calculateCashFlow() {
// Get Inputs
var grossRent = parseFloat(document.getElementById('grossRent').value) || 0;
var otherIncome = parseFloat(document.getElementById('otherIncome').value) || 0;
var mortgage = parseFloat(document.getElementById('mortgagePayment').value) || 0;
var taxIns = parseFloat(document.getElementById('taxInsurance').value) || 0;
var hoa = parseFloat(document.getElementById('hoaFees').value) || 0;
var vacancyPct = parseFloat(document.getElementById('vacancyRate').value) || 0;
var repairPct = parseFloat(document.getElementById('repairRate').value) || 0;
var mgmtPct = parseFloat(document.getElementById('managementRate').value) || 0;
// Calculations
var totalIncome = grossRent + otherIncome;
// Calculate variable costs based on Gross Rent
var vacancyCost = grossRent * (vacancyPct / 100);
var repairCost = grossRent * (repairPct / 100);
var mgmtCost = grossRent * (mgmtPct / 100);
var totalExpenses = mortgage + taxIns + hoa + vacancyCost + repairCost + mgmtCost;
var noi = totalIncome – (totalExpenses – mortgage); // NOI usually excludes debt service
var trueCashFlow = totalIncome – totalExpenses;
// Display Results
var resultBox = document.getElementById('results');
resultBox.style.display = 'block';
// Helper for currency format
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
});
document.getElementById('resTotalIncome').innerText = formatter.format(totalIncome);
document.getElementById('resTotalExpenses').innerText = formatter.format(totalExpenses);
// Note: NOI implies income minus operating expenses (excluding financing)
// Operating Expenses = Tax + Ins + HOA + Vacancy + Repair + Mgmt
var operatingExpenses = taxIns + hoa + vacancyCost + repairCost + mgmtCost;
var calculatedNOI = totalIncome – operatingExpenses;
document.getElementById('resNOI').innerText = formatter.format(calculatedNOI);
var cashFlowEl = document.getElementById('resCashFlow');
cashFlowEl.innerText = formatter.format(trueCashFlow);
if (trueCashFlow >= 0) {
cashFlowEl.className = 'positive';
} else {
cashFlowEl.className = 'negative';
}
}