Analyze your potential investment property profitability.
Monthly Income
$
$
Fixed Expenses
$
$
$
$
Variable Expenses
$
%
%
Capital Expenditures (CapEx)
$
Funds set aside for major replacements (roof, HVAC).
Analysis Results
Total Monthly Income$0.00
Total Monthly Expenses$0.00
Net Monthly Cash Flow$0.00
Annual Cash Flow$0.00
Operating Expense Ratio0%
function calculateCashFlow() {
// 1. Get Inputs (Income)
var rent = parseFloat(document.getElementById("monthlyRent").value) || 0;
var otherIncome = parseFloat(document.getElementById("otherIncome").value) || 0;
// 2. Get Inputs (Fixed Expenses)
var mortgage = parseFloat(document.getElementById("mortgagePayment").value) || 0;
var tax = parseFloat(document.getElementById("propertyTax").value) || 0;
var insurance = parseFloat(document.getElementById("insurance").value) || 0;
var hoa = parseFloat(document.getElementById("hoaFees").value) || 0;
// 3. Get Inputs (Variable & CapEx)
var repairs = parseFloat(document.getElementById("repairs").value) || 0;
var capex = parseFloat(document.getElementById("capex").value) || 0;
var vacancyRate = parseFloat(document.getElementById("vacancyRate").value) || 0;
var managementRate = parseFloat(document.getElementById("managementFee").value) || 0;
// 4. Calculate Variables
var totalIncome = rent + otherIncome;
// Calculate percentage based costs
var vacancyCost = totalIncome * (vacancyRate / 100);
var managementCost = totalIncome * (managementRate / 100);
// 5. Calculate Total Expenses
var totalExpenses = mortgage + tax + insurance + hoa + repairs + capex + vacancyCost + managementCost;
// 6. Calculate Cash Flow
var monthlyCashFlow = totalIncome – totalExpenses;
var annualCashFlow = monthlyCashFlow * 12;
var expenseRatio = 0;
if (totalIncome > 0) {
expenseRatio = (totalExpenses / totalIncome) * 100;
}
// 7. Update UI
document.getElementById("displayTotalIncome").innerText = "$" + totalIncome.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("displayTotalExpenses").innerText = "$" + totalExpenses.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
var cfElement = document.getElementById("displayCashFlow");
cfElement.innerText = "$" + monthlyCashFlow.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
// Color coding for cash flow
if (monthlyCashFlow >= 0) {
cfElement.className = "result-value highlight-positive";
} else {
cfElement.className = "result-value highlight-negative";
}
var annualElement = document.getElementById("displayAnnualCashFlow");
annualElement.innerText = "$" + annualCashFlow.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
if (annualCashFlow >= 0) {
annualElement.className = "result-value highlight-positive";
} else {
annualElement.className = "result-value highlight-negative";
}
document.getElementById("displayExpenseRatio").innerText = expenseRatio.toFixed(1) + "%";
// Show results
document.getElementById("resultContainer").style.display = "block";
}
Understanding Rental Property Cash Flow
Investing in real estate is one of the most reliable ways to build wealth, but the difference between a successful investment and a financial burden often comes down to one metric: Cash Flow. This calculator is designed to help investors accurately predict the monthly profit of a rental property by accounting for both obvious and hidden expenses.
What is Positive Cash Flow?
Positive cash flow occurs when a property's gross income exceeds all of the expenses associated with owning and operating it. This "net" income is money that goes straight into your pocket every month. Conversely, negative cash flow means you are paying out of pocket to keep the property running, which increases your financial risk.
Experienced investors typically look for properties that produce positive cash flow from day one, ensuring that the asset supports itself regardless of market appreciation.
The Hidden Costs of Being a Landlord
Many novice investors make the mistake of calculating cash flow by simply subtracting the mortgage payment from the rent. However, true profitability analysis requires accounting for "The 50% Rule" components:
Vacancy Rate: Properties won't be occupied 365 days a year. You must budget for turnover periods where you earn zero rent but still pay the mortgage.
CapEx (Capital Expenditures): This is a budget for major items that don't break monthly but will eventually need replacement, such as roofs, water heaters, and flooring.
Management Fees: Even if you self-manage now, allocating budget for a property manager ensures your numbers work if you decide to outsource later.
Maintenance: Leaky faucets and broken appliances are inevitable. Budgeting 5-10% of rent for general repairs is a standard safety net.
How to Interpret the Numbers
Cash Flow per Door: A common benchmark is $100-$200 per unit per month in pure cash flow. If this calculator shows a result lower than that, the margin for error may be too slim.
Operating Expense Ratio (OER): This metric compares your operating expenses to your income. A lower ratio generally indicates a more efficient property, though this varies by property age and class.
Frequently Asked Questions
What is a good cash flow for a rental property?
While goals vary, many investors aim for $100 to $200 per month per unit in net cash flow after all expenses and reserves. For ROI, a "Cash on Cash Return" of 8-12% is widely considered a solid investment target.
Should I include principal paydown in cash flow?
No. Cash flow is strictly the money left over after paying expenses. Principal paydown is a form of equity buildup (profit), but it is not liquid cash you can spend. It contributes to total ROI but not monthly cash flow.
What is CapEx in real estate?
CapEx, or Capital Expenditures, refers to funds used to upgrade or replace major physical assets of the property, such as a new roof, HVAC system, or structural repairs. Unlike routine maintenance, these are large, infrequent expenses that require saving over time.