Analyze your real estate investment profitability instantly.
Purchase & Loan Details
Income & Operating Expenses
Monthly Cash Flow$0.00
Cash on Cash Return0.00%
Monthly Mortgage (P&I)$0.00
Total Monthly Expenses$0.00
function calculateRental() {
// 1. Get Values
var price = parseFloat(document.getElementById('purchasePrice').value);
var downPercent = parseFloat(document.getElementById('downPayment').value);
var rate = parseFloat(document.getElementById('interestRate').value);
var term = parseFloat(document.getElementById('loanTerm').value);
var closingCosts = parseFloat(document.getElementById('closingCosts').value);
var rent = parseFloat(document.getElementById('monthlyRent').value);
var tax = parseFloat(document.getElementById('annualTax').value);
var insurance = parseFloat(document.getElementById('annualInsurance').value);
var hoa = parseFloat(document.getElementById('hoaFees').value);
var maintPercent = parseFloat(document.getElementById('maintenance').value);
// 2. Validate Inputs
if (isNaN(price) || isNaN(downPercent) || isNaN(rate) || isNaN(term) || isNaN(rent) || isNaN(tax) || isNaN(insurance)) {
alert("Please check your inputs. Ensure all required fields contain valid numbers.");
return;
}
// 3. Loan Calculations
var downAmount = price * (downPercent / 100);
var loanAmount = price – downAmount;
var monthlyRate = (rate / 100) / 12;
var totalPayments = term * 12;
// Monthly Mortgage Payment (Principal & Interest)
var monthlyMortgage = 0;
if (rate === 0) {
monthlyMortgage = loanAmount / totalPayments;
} else {
monthlyMortgage = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, totalPayments)) / (Math.pow(1 + monthlyRate, totalPayments) – 1);
}
// 4. Expense Calculations
var monthlyTax = tax / 12;
var monthlyInsurance = insurance / 12;
var monthlyMaintenance = rent * (maintPercent / 100);
// Total Monthly Expenses (Mortgage + Tax + Ins + HOA + Maint)
var totalMonthlyExpenses = monthlyMortgage + monthlyTax + monthlyInsurance + hoa + monthlyMaintenance;
// 5. Profitability Calculations
var monthlyCashFlow = rent – totalMonthlyExpenses;
var annualCashFlow = monthlyCashFlow * 12;
var totalInitialInvestment = downAmount + closingCosts;
// Cash on Cash Return
var cashOnCash = 0;
if (totalInitialInvestment > 0) {
cashOnCash = (annualCashFlow / totalInitialInvestment) * 100;
}
// 6. Display Results
var resCashFlow = document.getElementById('resCashFlow');
resCashFlow.innerHTML = "$" + monthlyCashFlow.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
// Color coding for cash flow
if(monthlyCashFlow >= 0) {
resCashFlow.style.color = "#2ecc71"; // Green
} else {
resCashFlow.style.color = "#e74c3c"; // Red
}
document.getElementById('resCoc').innerHTML = cashOnCash.toFixed(2) + "%";
// Color coding for CoC
var resCoc = document.getElementById('resCoc');
if(cashOnCash >= 0) {
resCoc.style.color = "#2ecc71";
} else {
resCoc.style.color = "#e74c3c";
}
document.getElementById('resMortgage').innerHTML = "$" + monthlyMortgage.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('resExpenses').innerHTML = "$" + totalMonthlyExpenses.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
// Show result section
document.getElementById('resultsArea').style.display = "block";
}
Understanding Rental Property Cash Flow
Investing in real estate is one of the most reliable ways to build long-term wealth, but not every property is a good investment. The difference between a profitable asset and a financial liability often comes down to one metric: Cash Flow. This calculator helps you analyze the numbers before you buy, ensuring you make data-driven investment decisions.
What is Positive Cash Flow?
Positive cash flow occurs when a property's gross rental income exceeds all of its expenses. These expenses include not just the mortgage payment, but also taxes, insurance, homeowner association (HOA) fees, and allowances for vacancy and maintenance.
For example, if you collect $2,000 in rent and your total monthly outflows are $1,500, your property generates $500 in positive cash flow every month. This surplus can be reinvested, saved for future repairs, or used as passive income.
Key Metrics Explained
When using this Rental Property Cash Flow Calculator, pay close attention to the following outputs:
Monthly Cash Flow: This is your net profit (or loss) every month. A negative number indicates that the property costs you money to hold, which is generally risky for beginners.
Cash on Cash Return (CoC): This percentage measures the annual return on the actual cash you invested (down payment + closing costs), rather than the total value of the property. It is often considered the most important metric for gauging the efficiency of your investment capital.
Maintenance & Vacancy Reserves: Many new investors make the mistake of ignoring these costs. Even if a property is currently rented and in good condition, you should always budget a percentage of rent (typically 5-10% each) for future repairs and periods where the unit sits empty.
What is a Good Cash on Cash Return?
Target returns vary by market and investor strategy. However, a general rule of thumb for many residential real estate investors is to aim for a Cash on Cash return of 8% to 12%. In highly appreciative markets (where property values rise quickly), investors might accept a lower CoC (4-6%) in exchange for long-term equity growth. In markets with lower appreciation, investors typically demand higher immediate cash flow (12%+).
How to Improve Cash Flow
If the calculator shows a negative or low cash flow, consider these adjustments:
Increase the Down Payment: Putting more money down reduces the loan amount and the monthly mortgage payment, instantly boosting monthly cash flow.
Negotiate the Purchase Price: A lower purchase price reduces your loan basis and property taxes.
Raise Rental Income: Investigate if minor renovations (like new flooring or paint) could justify a higher monthly rent.
Shop for Insurance: Insurance premiums vary significantly; getting quotes from multiple carriers can reduce monthly expenses.