Please enter valid numerical values for all required fields.
Investment Performance
Monthly Cash Flow:$0.00
Cash on Cash Return (ROI):0.00%
Monthly Mortgage (P&I):$0.00
Total Monthly Expenses:$0.00
Total Cash Invested:$0.00
function calculateRentalROI() {
// 1. Get Elements
var priceEl = document.getElementById('rpc-price');
var repairEl = document.getElementById('rpc-repair');
var downEl = document.getElementById('rpc-down');
var rateEl = document.getElementById('rpc-rate');
var termEl = document.getElementById('rpc-term');
var rentEl = document.getElementById('rpc-rent');
var taxEl = document.getElementById('rpc-tax');
var insEl = document.getElementById('rpc-ins');
var hoaEl = document.getElementById('rpc-hoa');
var vacancyEl = document.getElementById('rpc-vacancy');
var resultBox = document.getElementById('rpc-result');
var errorBox = document.getElementById('rpc-error-msg');
// 2. Parse Values
var price = parseFloat(priceEl.value);
var repair = parseFloat(repairEl.value) || 0;
var downPercent = parseFloat(downEl.value);
var rate = parseFloat(rateEl.value);
var term = parseFloat(termEl.value);
var rent = parseFloat(rentEl.value);
var tax = parseFloat(taxEl.value);
var ins = parseFloat(insEl.value);
var hoa = parseFloat(hoaEl.value) || 0;
var vacancyPercent = parseFloat(vacancyEl.value) || 0;
// 3. Validation
if (isNaN(price) || isNaN(downPercent) || isNaN(rate) || isNaN(term) || isNaN(rent) || isNaN(tax) || isNaN(ins)) {
errorBox.style.display = 'block';
resultBox.style.display = 'none';
return;
}
errorBox.style.display = 'none';
// 4. Calculations
// Loan Calculation
var downPaymentAmount = price * (downPercent / 100);
var loanAmount = price – downPaymentAmount;
var monthlyRate = (rate / 100) / 12;
var numberOfPayments = term * 12;
// Monthly Mortgage (Principal + Interest)
// Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
var monthlyMortgage = 0;
if (rate === 0) {
monthlyMortgage = loanAmount / numberOfPayments;
} else {
monthlyMortgage = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, numberOfPayments)) / (Math.pow(1 + monthlyRate, numberOfPayments) – 1);
}
// Monthly Expenses
var monthlyTax = tax / 12;
var monthlyIns = ins / 12;
var monthlyVacancy = rent * (vacancyPercent / 100);
var totalMonthlyExpenses = monthlyMortgage + monthlyTax + monthlyIns + hoa + monthlyVacancy;
// Cash Flow
var monthlyCashFlow = rent – totalMonthlyExpenses;
var annualCashFlow = monthlyCashFlow * 12;
// Cash on Cash Return
// Initial Investment = Down Payment + Repairs + Closing Costs (Estimate included in repairs input for simplicity)
var totalInitialInvestment = downPaymentAmount + repair;
var cocReturn = (annualCashFlow / totalInitialInvestment) * 100;
// 5. Update UI
document.getElementById('res-cashflow').innerText = "$" + monthlyCashFlow.toFixed(2).replace(/\B(?=(\d{3})+(?!\d))/g, ",");
document.getElementById('res-cashflow').style.color = monthlyCashFlow >= 0 ? '#27ae60' : '#e74c3c';
document.getElementById('res-coc').innerText = cocReturn.toFixed(2) + "%";
document.getElementById('res-coc').style.color = cocReturn >= 0 ? '#27ae60' : '#e74c3c';
document.getElementById('res-mortgage').innerText = "$" + monthlyMortgage.toFixed(2).replace(/\B(?=(\d{3})+(?!\d))/g, ",");
document.getElementById('res-expenses').innerText = "$" + totalMonthlyExpenses.toFixed(2).replace(/\B(?=(\d{3})+(?!\d))/g, ",");
document.getElementById('res-invested').innerText = "$" + totalInitialInvestment.toFixed(2).replace(/\B(?=(\d{3})+(?!\d))/g, ",");
resultBox.style.display = 'block';
}
Understanding Rental Property ROI
Investing in real estate is one of the most reliable ways to build wealth, but simply buying a property and renting it out doesn't guarantee a profit. To be a successful investor, you must understand the numbers behind the deal. This Rental Property ROI Calculator is designed to help you analyze the profitability of a potential investment by calculating two critical metrics: Monthly Cash Flow and Cash-on-Cash Return.
Key Metrics Explained
1. Monthly Cash Flow
Cash flow is the net income from a real estate investment after mortgage payments and operating expenses have been made. Positive cash flow ensures that the property pays for itself and provides you with passive income.
Formula: Rent – (Mortgage + Taxes + Insurance + HOA + Maintenance + Vacancy)
2. Cash-on-Cash Return (CoC)
This is arguably the most important metric for rental investors. It measures the annual return you make on the actual cash you invested (down payment + closing costs + rehab), rather than the total price of the property. It allows you to compare real estate returns against other investments like stocks or bonds.
Formula: (Annual Cash Flow / Total Cash Invested) x 100
How to Estimate Expenses
Many new investors make the mistake of underestimating expenses. When using the calculator, be sure to account for:
Vacancy Rate: Properties won't be rented 365 days a year. A standard safe estimate is 5-8%.
Maintenance (CapEx): Roofs leak and water heaters break. Setting aside 5-10% of the rent for repairs ensures you aren't caught off guard.
Property Management: If you aren't managing the tenant yourself, expect to pay 8-10% of the monthly rent to a management company.
What is a Good ROI?
While "good" is subjective, many investors target a Cash-on-Cash return of 8% to 12%. In highly appreciative markets, investors might accept a lower cash flow (4-6%) in exchange for long-term equity growth. Conversely, in stable, low-appreciation markets, investors often demand higher cash flow (12%+) to offset the lack of value growth.