How to Calculate Weighted Average Interest Rate for Fixed Deposit
by
Rental Property ROI & Cash Flow Calculator
Purchase Details
Monthly Financials
Monthly Mortgage
$0
Monthly Cash Flow
$0
Cap Rate
0%
Cash on Cash Return
0%
function calculateRentalROI() {
var price = parseFloat(document.getElementById('purchasePrice').value);
var downPct = parseFloat(document.getElementById('downPaymentPercent').value);
var rate = parseFloat(document.getElementById('interestRate').value);
var term = parseFloat(document.getElementById('loanTerm').value);
var rent = parseFloat(document.getElementById('monthlyRent').value);
var tax = parseFloat(document.getElementById('monthlyTaxes').value);
var ins = parseFloat(document.getElementById('monthlyInsurance').value);
var maint = parseFloat(document.getElementById('monthlyMaintenance').value);
if (isNaN(price) || isNaN(rent) || isNaN(downPct)) {
alert("Please fill in the core property details.");
return;
}
// Mortgage Calculation
var downPaymentAmount = price * (downPct / 100);
var loanAmount = price – downPaymentAmount;
var monthlyRate = (rate / 100) / 12;
var numPayments = term * 12;
var monthlyMortgage = 0;
if (rate > 0) {
monthlyMortgage = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, numPayments)) / (Math.pow(1 + monthlyRate, numPayments) – 1);
} else {
monthlyMortgage = loanAmount / numPayments;
}
// Financial Metrics
var totalOperatingExpenses = tax + ins + maint;
var monthlyCashFlow = rent – (monthlyMortgage + totalOperatingExpenses);
var annualNOI = (rent – totalOperatingExpenses) * 12;
var capRate = (annualNOI / price) * 100;
var annualCashFlow = monthlyCashFlow * 12;
var cashOnCash = (annualCashFlow / downPaymentAmount) * 100;
// Display
document.getElementById('roi-results').style.display = 'block';
document.getElementById('resMortgage').innerText = '$' + monthlyMortgage.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('resCashFlow').innerText = '$' + monthlyCashFlow.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('resCapRate').innerText = capRate.toFixed(2) + '%';
document.getElementById('resCoC').innerText = cashOnCash.toFixed(2) + '%';
// Color coding cash flow
document.getElementById('resCashFlow').style.color = monthlyCashFlow >= 0 ? '#27ae60' : '#c0392b';
}
How to Calculate Rental Property ROI
Investing in real estate is one of the most reliable ways to build wealth, but only if the numbers make sense. Our Rental Property ROI Calculator helps you peel back the layers of a potential deal to see the true profitability beyond just the monthly rent check.
Key Metrics Explained
Cap Rate (Capitalization Rate): This measures the property's natural rate of return without considering financing. It is calculated by dividing the Net Operating Income (NOI) by the purchase price. A "good" cap rate typically falls between 4% and 10%, depending on the market.
Cash on Cash Return (CoC): This is often the most important metric for investors using leverage (mortgages). It measures the annual cash flow relative to the actual cash you invested (your down payment).
Monthly Cash Flow: This is the "take-home" profit after every single expense—mortgage, taxes, insurance, and maintenance—has been paid.
Example Calculation
Imagine you buy a property for $300,000 with a 20% down payment ($60,000).
If your total monthly expenses (mortgage + taxes + insurance + maintenance) equal $2,100 and you rent it out for $2,500, your monthly cash flow is $400.
Your annual cash flow would be $4,800. Dividing that $4,800 by your $60,000 investment gives you an 8% Cash on Cash Return.
Why Accuracy Matters
Many novice investors forget to account for "hidden" costs like vacancies or capital expenditures (roof repairs, HVAC replacement). When using the calculator, always be conservative with your expense estimates to ensure your investment remains "in the black" even during tough months.