Rental Property Cash Flow Calculator
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Cash on Cash Return
0.00%
Detailed Monthly Breakdown
Gross Rent:
$0
– Operating Expenses:
$0
= Net Operating Income (NOI):
$0
– Mortgage Payment (P&I):
$0
= Total Cash Flow:
$0
Understanding Rental Property Cash Flow
Cash flow is the lifeblood of any real estate investment. It represents the net income generated by a property after all expenses, including mortgage payments, are paid. A positive cash flow means the property pays for itself and puts money in your pocket every month.
Key Metrics: Cap Rate vs. Cash on Cash Return
When analyzing a rental property, it is crucial to understand the difference between Cap Rate and Cash on Cash (CoC) Return:
- Cap Rate (Capitalization Rate): This metric measures the property's natural rate of return assuming you bought it with all cash. It is calculated by dividing the Net Operating Income (NOI) by the purchase price. It helps compare the profitability of different properties regardless of financing.
- Cash on Cash Return: This metric shows the return on the actual cash you invested (down payment + closing costs). It accounts for leverage (the mortgage) and is often a better indicator of your personalized return on investment (ROI).
How Operating Expenses Affect Profitability
Many new investors make the mistake of only subtracting the mortgage payment from the rent. To accurately calculate cash flow, you must account for all operating expenses, including:
- Vacancy: Money set aside for periods when the property has no tenant.
- Repairs & Maintenance: Ongoing costs to fix minor issues like leaky faucets or painting.
- CapEx (Capital Expenditures): Savings for big-ticket items like a new roof, HVAC, or flooring replacement.
- Management Fees: The cost of hiring a professional property manager (usually 8-10% of rent).
Using a detailed Rental Property Cash Flow Calculator ensures you don't overlook these costs, preventing you from buying a property that loses money.
function calculateCashFlow() {
// Get Inputs
var price = parseFloat(document.getElementById('purchasePrice').value) || 0;
var downPayment = parseFloat(document.getElementById('downPayment').value) || 0;
var closingCosts = parseFloat(document.getElementById('closingCosts').value) || 0;
var interestRate = parseFloat(document.getElementById('interestRate').value) || 0;
var termYears = parseFloat(document.getElementById('loanTerm').value) || 0;
var monthlyRent = parseFloat(document.getElementById('monthlyRent').value) || 0;
var annualTax = parseFloat(document.getElementById('annualTax').value) || 0;
var annualInsurance = parseFloat(document.getElementById('annualInsurance').value) || 0;
var monthlyHOA = parseFloat(document.getElementById('hoaFee').value) || 0;
var vacancyRate = parseFloat(document.getElementById('vacancyRate').value) || 0;
var repairRate = parseFloat(document.getElementById('repairRate').value) || 0;
var capexRate = parseFloat(document.getElementById('capexRate').value) || 0;
var managementRate = parseFloat(document.getElementById('managementRate').value) || 0;
// 1. Calculate Mortgage Payment (Principal & Interest)
var loanAmount = price – downPayment;
var monthlyRate = (interestRate / 100) / 12;
var numberOfPayments = termYears * 12;
var monthlyMortgage = 0;
if (loanAmount > 0 && interestRate > 0) {
monthlyMortgage = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, numberOfPayments)) / (Math.pow(1 + monthlyRate, numberOfPayments) – 1);
} else if (loanAmount > 0 && interestRate === 0) {
monthlyMortgage = loanAmount / numberOfPayments;
}
// 2. Calculate Monthly Expenses
var monthlyTax = annualTax / 12;
var monthlyInsurance = annualInsurance / 12;
// Variable expenses based on rent percentages
var vacancyCost = monthlyRent * (vacancyRate / 100);
var repairCost = monthlyRent * (repairRate / 100);
var capexCost = monthlyRent * (capexRate / 100);
var managementCost = monthlyRent * (managementRate / 100);
var totalOperatingExpenses = monthlyTax + monthlyInsurance + monthlyHOA + vacancyCost + repairCost + capexCost + managementCost;
// 3. Calculate NOI (Net Operating Income)
var monthlyNOI = monthlyRent – totalOperatingExpenses;
var annualNOI = monthlyNOI * 12;
// 4. Calculate Cash Flow
var monthlyCashFlow = monthlyNOI – monthlyMortgage;
var annualCashFlow = monthlyCashFlow * 12;
// 5. Calculate Metrics
var totalCashInvested = downPayment + closingCosts;
var cocReturn = 0;
if (totalCashInvested > 0) {
cocReturn = (annualCashFlow / totalCashInvested) * 100;
}
var capRate = 0;
if (price > 0) {
capRate = (annualNOI / price) * 100;
}
// Update DOM
// Helper for currency formatting
var fmtMoney = new Intl.NumberFormat('en-US', { style: 'currency', currency: 'USD' });
var fmtPct = new Intl.NumberFormat('en-US', { style: 'percent', minimumFractionDigits: 2, maximumFractionDigits: 2 });
document.getElementById('resultCashFlow').textContent = fmtMoney.format(monthlyCashFlow);
// Color coding cash flow
var cfElement = document.getElementById('resultCashFlow');
if(monthlyCashFlow >= 0) {
cfElement.classList.remove('negative');
cfElement.classList.add('positive');
} else {
cfElement.classList.remove('positive');
cfElement.classList.add('negative');
}
document.getElementById('resultCoC').textContent = fmtPct.format(cocReturn / 100); // format expects 0-1
document.getElementById('resultCapRate').textContent = fmtPct.format(capRate / 100);
// Breakdown table
document.getElementById('displayRent').textContent = fmtMoney.format(monthlyRent);
document.getElementById('displayExpenses').textContent = fmtMoney.format(totalOperatingExpenses);
document.getElementById('displayNOI').textContent = fmtMoney.format(monthlyNOI);
document.getElementById('displayMortgage').textContent = fmtMoney.format(monthlyMortgage);
document.getElementById('displayTotalFlow').textContent = fmtMoney.format(monthlyCashFlow);
}
// Initialize calculation on load
window.onload = function() {
calculateCashFlow();
};