Analyze cash flow, cap rate, and cash-on-cash return for your real estate investment.
(Taxes, Ins, Maint, HOA)
Monthly Cash Flow:$0.00
Cash on Cash Return (ROI):0.00%
Cap Rate:0.00%
Total Initial Cash Invested:$0.00
Monthly Mortgage Payment:$0.00
Net Operating Income (Annual):$0.00
function calculateROI() {
// Get Input Values
var price = parseFloat(document.getElementById('purchasePrice').value);
var closing = parseFloat(document.getElementById('closingCosts').value);
var downPct = parseFloat(document.getElementById('downPaymentPercent').value);
var rate = parseFloat(document.getElementById('interestRate').value);
var term = parseFloat(document.getElementById('loanTerm').value);
var rent = parseFloat(document.getElementById('monthlyRent').value);
var expenses = parseFloat(document.getElementById('monthlyExpenses').value);
var vacancy = parseFloat(document.getElementById('vacancyRate').value);
// Validation
if (isNaN(price) || isNaN(rent)) {
alert("Please enter valid numbers for Price and Rent.");
return;
}
// Calculations
var downAmount = price * (downPct / 100);
var loanAmount = price – downAmount;
var totalInvested = downAmount + closing;
// Mortgage Calculation
var monthlyRate = rate / 100 / 12;
var numPayments = term * 12;
var mortgagePayment = 0;
if (rate === 0) {
mortgagePayment = loanAmount / numPayments;
} else {
mortgagePayment = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, numPayments)) / (Math.pow(1 + monthlyRate, numPayments) – 1);
}
// Income & Expense Calculations
var vacancyLoss = rent * (vacancy / 100);
var effectiveGrossIncome = rent – vacancyLoss;
var totalMonthlyExpenses = expenses + mortgagePayment;
// Core Metrics
var monthlyCashFlow = effectiveGrossIncome – totalMonthlyExpenses;
var annualCashFlow = monthlyCashFlow * 12;
var annualNOI = (effectiveGrossIncome – expenses) * 12; // NOI excludes debt service
var cocRoi = 0;
if (totalInvested > 0) {
cocRoi = (annualCashFlow / totalInvested) * 100;
}
var capRate = 0;
if (price > 0) {
capRate = (annualNOI / price) * 100;
}
// Display Results
document.getElementById('resultsArea').style.display = 'block';
// Formatting Helper
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
});
// Update DOM
var cashFlowEl = document.getElementById('resCashFlow');
cashFlowEl.innerHTML = formatter.format(monthlyCashFlow);
if (monthlyCashFlow >= 0) {
cashFlowEl.className = "result-value highlight-positive";
} else {
cashFlowEl.className = "result-value highlight-negative";
}
document.getElementById('resCocRoi').innerHTML = cocRoi.toFixed(2) + "%";
document.getElementById('resCapRate').innerHTML = capRate.toFixed(2) + "%";
document.getElementById('resCashInvested').innerHTML = formatter.format(totalInvested);
document.getElementById('resMortgage').innerHTML = formatter.format(mortgagePayment);
document.getElementById('resNOI').innerHTML = formatter.format(annualNOI);
}
Understanding Rental Property ROI
Investing in real estate is one of the most reliable ways to build wealth, but not every property is a good deal. To succeed, you must look beyond the purchase price and analyze the numbers. This Rental Property ROI Calculator helps investors determine the profitability of a potential rental unit by calculating key metrics like Cash Flow, Cap Rate, and Cash on Cash Return.
Key Metrics Explained
When analyzing a rental property, there are three primary numbers you should focus on:
Monthly Cash Flow: This is the money left in your pocket after all expenses are paid. It is calculated as: Rental Income – (Mortgage + Taxes + Insurance + Maintenance + Vacancy). Positive cash flow ensures the property pays for itself.
Cash on Cash Return (CoC ROI): This measures the return on the actual cash you invested (down payment + closing costs), rather than the total loan amount. A CoC return of 8-12% is often considered a solid benchmark for residential rentals.
Cap Rate (Capitalization Rate): This metric evaluates the profitability of a property regardless of financing. It is calculated by dividing the Net Operating Income (NOI) by the purchase price. It helps compare properties as if they were bought with 100% cash.
How to Estimate Expenses
One of the biggest mistakes new investors make is underestimating expenses. Beyond the mortgage, you must account for:
Vacancy Rate: Properties won't be rented 365 days a year. A standard vacancy allowance is 5% to 10%.
Maintenance & CapEx: Roofs leak and water heaters break. Setting aside 10-15% of rent for repairs is prudent.
Property Management: If you hire a professional manager, expect to pay 8-10% of the monthly rent.
Using the Calculator
To get the most accurate results, input the purchase price, your financing terms, and conservative estimates for rental income and expenses. Adjust the "Down Payment" and "Interest Rate" fields to see how leverage impacts your Cash on Cash Return. Remember, a property with a high Cap Rate might still have negative cash flow if the financing terms are unfavorable.