Analyze the profitability of your real estate investment instantly.
Purchase Information
Monthly Income
Expenses (Monthly/Yearly as noted)
Please enter valid positive numbers for all fields.
Investment Analysis
Monthly Cash Flow$0.00
Net Operating Income (NOI) / Month$0.00
Total Monthly Expenses$0.00
Monthly Mortgage Payment (P&I)$0.00
Return Metrics
Cash on Cash Return0.00%
Cap Rate0.00%
Total Cash Invested$0.00
How to Use the Rental Property Cash Flow Calculator
Successful real estate investing relies on accurate math, not gut feelings. This Rental Property Cash Flow Calculator helps investors determine the viability of a potential investment property by analyzing income, expenses, and key return metrics.
Why Cash Flow Matters
Cash flow is the net amount of cash moving into and out of a business. In real estate, positive cash flow means the property's income exceeds all expenses (including the mortgage). This "passive income" is the holy grail for buy-and-hold investors. Negative cash flow, or an "alligator," eats up your monthly reserves and increases investment risk.
Understanding the Input Fields
Purchase Price: The agreed-upon price to buy the property.
Down Payment: The percentage of the purchase price paid upfront (typically 20-25% for investment properties).
Vacancy Rate: An estimate of time the property sits empty. A safe conservative estimate is often 5-8%.
Management Fee: If you hire a property manager, they typically charge 8-10% of the monthly rent. If you self-manage, this is 0%, but you pay with your time.
CapEx & Maintenance: Funds set aside for repairs (leaky faucets) and capital expenditures (new roof, HVAC). Setting aside 5-10% of rent is industry standard.
Key Investment Metrics Explained
1. Net Operating Income (NOI)
NOI is a calculation used to analyze the profitability of income-generating real estate investments. It equals all revenue from the property, minus all reasonably necessary operating expenses. Crucially, NOI excludes the mortgage payment. It represents the property's potential regardless of how it is financed.
2. Cash on Cash Return (CoC)
This is arguably the most important metric for investors. It measures the annual return on the actual cash you invested.
For example, if you invest $50,000 (down payment + closing costs) and the property generates $5,000 a year in clear profit, your CoC return is 10%. This allows you to compare real estate against other investments like stocks or bonds.
3. Capitalization Rate (Cap Rate)
Cap Rate measures the rate of return on a real estate investment property based on the income that the property is expected to generate. It is calculated by dividing the Net Operating Income (NOI) by the current market value (Purchase Price).
Formula: (Annual NOI / Purchase Price) × 100
Cap rates are useful for comparing similar properties in the same market, assuming you paid cash for them.
What is a "Good" Return?
While subjective, many investors look for:
Cash Flow: At least $100-$200 per door, per month.
Cash on Cash Return: 8-12% or higher.
Cap Rate: 5-10%, depending on the risk level and location of the asset.
function calculateCashFlow() {
// 1. Get Inputs
var price = parseFloat(document.getElementById('purchasePrice').value);
var downPercent = parseFloat(document.getElementById('downPayment').value);
var interestRate = parseFloat(document.getElementById('interestRate').value);
var termYears = parseFloat(document.getElementById('loanTerm').value);
var closingCosts = parseFloat(document.getElementById('closingCosts').value);
var rent = parseFloat(document.getElementById('monthlyRent').value);
var otherIncome = parseFloat(document.getElementById('otherIncome').value);
var taxYearly = parseFloat(document.getElementById('propertyTax').value);
var insuranceYearly = parseFloat(document.getElementById('insurance').value);
var hoaMonthly = parseFloat(document.getElementById('hoa').value);
var maintPercent = parseFloat(document.getElementById('maintenance').value);
var vacancyPercent = parseFloat(document.getElementById('vacancy').value);
var mgmtPercent = parseFloat(document.getElementById('management').value);
// Validation
if (isNaN(price) || isNaN(rent) || isNaN(interestRate) || price 0) {
monthlyMortgage = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, numPayments)) / (Math.pow(1 + monthlyRate, numPayments) – 1);
} else {
monthlyMortgage = loanAmount / numPayments;
}
// 3. Expense Calculations
var totalMonthlyIncome = rent + otherIncome;
// Variable expenses based on income
var vacancyCost = totalMonthlyIncome * (vacancyPercent / 100);
var maintCost = totalMonthlyIncome * (maintPercent / 100);
var mgmtCost = totalMonthlyIncome * (mgmtPercent / 100);
// Fixed monthly expenses
var taxMonthly = taxYearly / 12;
var insuranceMonthly = insuranceYearly / 12;
var operatingExpenses = taxMonthly + insuranceMonthly + hoaMonthly + maintCost + vacancyCost + mgmtCost;
var totalExpenses = operatingExpenses + monthlyMortgage;
// 4. Result Metrics
var noiMonthly = totalMonthlyIncome – operatingExpenses;
var cashFlowMonthly = noiMonthly – monthlyMortgage;
var cashFlowYearly = cashFlowMonthly * 12;
var noiYearly = noiMonthly * 12;
var totalCashInvested = downPaymentAmount + closingCosts;
// Avoid division by zero
var cocReturn = 0;
if (totalCashInvested > 0) {
cocReturn = (cashFlowYearly / totalCashInvested) * 100;
}
var capRate = 0;
if (price > 0) {
capRate = (noiYearly / price) * 100;
}
// 5. Update UI
// Helper formatter
var fmtMoney = new Intl.NumberFormat('en-US', { style: 'currency', currency: 'USD' });
var fmtPct = new Intl.NumberFormat('en-US', { style: 'percent', minimumFractionDigits: 2 });
document.getElementById('resCashFlow').innerHTML = fmtMoney.format(cashFlowMonthly);
document.getElementById('resNOI').innerHTML = fmtMoney.format(noiMonthly);
document.getElementById('resTotalExp').innerHTML = fmtMoney.format(totalExpenses);
document.getElementById('resMortgage').innerHTML = fmtMoney.format(monthlyMortgage);
document.getElementById('resCoC').innerHTML = cocReturn.toFixed(2) + "%";
document.getElementById('resCapRate').innerHTML = capRate.toFixed(2) + "%";
document.getElementById('resCashInvested').innerHTML = fmtMoney.format(totalCashInvested);
// Color coding cash flow
var flowEl = document.getElementById('resCashFlow');
if (cashFlowMonthly >= 0) {
flowEl.style.color = '#27ae60';
} else {
flowEl.style.color = '#c0392b';
}
document.getElementById('results').style.display = 'block';
}