Analyze your potential real estate investment returns instantly.
Monthly Mortgage P&I:$0.00
Operating Expenses + Vacancy:$0.00
Total Monthly Outflow:$0.00
Monthly Cash Flow:$0.00
Annual Cash Flow:$0.00
Cash on Cash Return (CoC):0.00%
function calculateRentalCashFlow() {
// 1. Get Input Values
var price = parseFloat(document.getElementById("rpcPrice").value);
var downPayment = parseFloat(document.getElementById("rpcDownPayment").value);
var rate = parseFloat(document.getElementById("rpcInterestRate").value);
var years = parseFloat(document.getElementById("rpcLoanTerm").value);
var rent = parseFloat(document.getElementById("rpcRent").value);
var vacancyRate = parseFloat(document.getElementById("rpcVacancy").value);
var otherExpenses = parseFloat(document.getElementById("rpcExpenses").value);
// 2. Validation
if (isNaN(price) || isNaN(downPayment) || isNaN(rate) || isNaN(years) || isNaN(rent) || isNaN(vacancyRate) || isNaN(otherExpenses)) {
alert("Please fill in all fields with valid numbers.");
return;
}
// 3. Loan Calculations
var loanAmount = price – downPayment;
var monthlyRate = (rate / 100) / 12;
var numberOfPayments = years * 12;
var monthlyMortgage = 0;
if (rate === 0) {
monthlyMortgage = loanAmount / numberOfPayments;
} else {
monthlyMortgage = (loanAmount * monthlyRate * Math.pow(1 + monthlyRate, numberOfPayments)) / (Math.pow(1 + monthlyRate, numberOfPayments) – 1);
}
// 4. Operating Expenses Calculation
var monthlyVacancyCost = rent * (vacancyRate / 100);
var totalOperatingExpenses = otherExpenses + monthlyVacancyCost;
// 5. Cash Flow Calculation
var totalMonthlyOutflow = monthlyMortgage + totalOperatingExpenses;
var monthlyCashFlow = rent – totalMonthlyOutflow;
var annualCashFlow = monthlyCashFlow * 12;
// 6. Return Metrics
// Cash on Cash = Annual Pre-Tax Cash Flow / Total Cash Invested
// Assuming Closing Costs are 0 for simplicity in this specific calculator version,
// or assuming user included them in Down Payment if they wanted to track total cash.
var totalCashInvested = downPayment;
var cocReturn = 0;
if (totalCashInvested > 0) {
cocReturn = (annualCashFlow / totalCashInvested) * 100;
}
// 7. Format Output Function
function formatMoney(num) {
return "$" + num.toFixed(2).replace(/\d(?=(\d{3})+\.)/g, '$&,');
}
// 8. Display Results
document.getElementById("dispMortgage").innerText = formatMoney(monthlyMortgage);
document.getElementById("dispOpExp").innerText = formatMoney(totalOperatingExpenses);
document.getElementById("dispOutflow").innerText = formatMoney(totalMonthlyOutflow);
var cfEl = document.getElementById("dispCashFlow");
cfEl.innerText = formatMoney(monthlyCashFlow);
cfEl.className = "rpc-result-value " + (monthlyCashFlow >= 0 ? "positive" : "negative");
var acfEl = document.getElementById("dispAnnualCF");
acfEl.innerText = formatMoney(annualCashFlow);
acfEl.className = "rpc-result-value " + (annualCashFlow >= 0 ? "positive" : "negative");
var cocEl = document.getElementById("dispCoC");
cocEl.innerText = cocReturn.toFixed(2) + "%";
cocEl.className = "rpc-result-value " + (cocReturn >= 0 ? "positive" : "negative");
// Show result div
document.getElementById("rpcResult").style.display = "block";
}
Understanding Rental Property Cash Flow
Investing in real estate is one of the most reliable ways to build wealth, but the success of an investment property hinges on one critical metric: Cash Flow. This calculator helps investors determine the viability of a rental property by analyzing income, expenses, and financing costs.
What is Positive vs. Negative Cash Flow?
Positive Cash Flow occurs when a property's monthly rental income exceeds all its expenses, including the mortgage, taxes, insurance, and maintenance. This is the goal for most buy-and-hold investors, as it provides passive income.
Negative Cash Flow happens when the expenses exceed the income. While some investors accept negative cash flow in anticipation of high property appreciation, it carries significantly higher risk. If the property sits vacant or requires major repairs, the investor must pay out of pocket to keep the asset.
Key Inputs Explained
Vacancy Rate: No property is occupied 100% of the time. A standard vacancy rate to factor in is 5% to 10% (equivalent to 2-4 weeks of vacancy per year). This ensures your calculations are conservative and realistic.
Monthly Expenses: Novice investors often overlook "hidden" costs. Beyond the mortgage, ensure you account for Property Management (typically 8-10% of rent), CapEx (Capital Expenditures for roof/HVAC replacement), Repairs, HOA fees, and Property Taxes.
Cash on Cash Return (CoC): This metric measures the annual return on the actual cash you invested (down payment + closing costs). It is often considered a better metric than simple ROI because it accounts for leverage.
How to Use This Calculator
To get an accurate result, research comparable rentals in the area to estimate the Monthly Rental Income accurately. Input your loan details carefully, as the interest rate significantly impacts your monthly outflow. Finally, be honest with your expense estimates. Underestimating repairs is the most common mistake leading to unexpected negative cash flow.
What is a "Good" Cash on Cash Return?
While targets vary by market and strategy, many real estate investors aim for a Cash on Cash return of 8% to 12%. In highly appreciative markets, investors might accept a lower return (4-6%), while in stable cash-flow markets, they may demand 15% or higher.