Please check your inputs. Ensure values are positive numbers.
Monthly Analysis
Gross Income:$0.00
Mortgage Payment (P&I):$0.00
Total Monthly Expenses (Operating + P&I):$0.00
Monthly Cash Flow:$0.00
Investment Returns
Total Cash Invested:$0.00
Cap Rate:0.00%
Cash on Cash Return:0.00%
function calculateRentalROI() {
// Get Inputs
var price = parseFloat(document.getElementById('calc_price').value);
var down = parseFloat(document.getElementById('calc_down').value);
var closing = parseFloat(document.getElementById('calc_closing').value);
var rate = parseFloat(document.getElementById('calc_rate').value);
var term = parseFloat(document.getElementById('calc_term').value);
var rent = parseFloat(document.getElementById('calc_rent').value);
var tax = parseFloat(document.getElementById('calc_tax').value);
var insurance = parseFloat(document.getElementById('calc_insurance').value);
var hoa = parseFloat(document.getElementById('calc_hoa').value);
var vacancyRate = parseFloat(document.getElementById('calc_vacancy').value);
var maintRate = parseFloat(document.getElementById('calc_maint').value);
var errorDiv = document.getElementById('rp_error');
var resultsDiv = document.getElementById('rp_results');
// Validation
if (isNaN(price) || isNaN(down) || isNaN(rent) || isNaN(rate) || price < 0 || rent 0) {
mortgage = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, totalMonths)) / (Math.pow(1 + monthlyRate, totalMonths) – 1);
} else {
mortgage = loanAmount / totalMonths;
}
// Monthly Expenses Breakdown
var monthlyTax = tax / 12;
var monthlyInsurance = insurance / 12;
var vacancyCost = rent * (vacancyRate / 100);
var maintCost = rent * (maintRate / 100);
var operatingExpenses = monthlyTax + monthlyInsurance + hoa + vacancyCost + maintCost;
var totalExpenses = operatingExpenses + mortgage;
// Cash Flow
var monthlyCashFlow = rent – totalExpenses;
var annualCashFlow = monthlyCashFlow * 12;
// Investment Metrics
var totalInvested = down + closing;
// Net Operating Income (NOI) = Income – Operating Expenses (No Mortgage)
var annualNOI = (rent * 12) – (operatingExpenses * 12);
var capRate = (annualNOI / price) * 100;
var cocReturn = (annualCashFlow / totalInvested) * 100;
// Formatting Helper
function formatMoney(num) {
return '$' + num.toFixed(2).replace(/\d(?=(\d{3})+\.)/g, '$&,');
}
// Display Results
document.getElementById('res_income').innerHTML = formatMoney(rent);
document.getElementById('res_mortgage').innerHTML = formatMoney(mortgage);
document.getElementById('res_expenses').innerHTML = formatMoney(totalExpenses);
var cfElem = document.getElementById('res_cashflow');
cfElem.innerHTML = formatMoney(monthlyCashFlow);
cfElem.style.color = monthlyCashFlow >= 0 ? '#27ae60' : '#c0392b';
document.getElementById('res_invested').innerHTML = formatMoney(totalInvested);
document.getElementById('res_caprate').innerHTML = capRate.toFixed(2) + '%';
var cocElem = document.getElementById('res_coc');
cocElem.innerHTML = cocReturn.toFixed(2) + '%';
cocElem.style.color = cocReturn >= 0 ? '#27ae60' : '#c0392b';
resultsDiv.style.display = 'block';
}
Understanding Rental Property Cash Flow Analysis
Investing in real estate is a powerful vehicle for building wealth, but success hinges on the numbers. A Rental Property Calculator is an essential tool for investors to evaluate the profitability of a potential purchase before signing any contracts. It moves beyond simple "napkin math" to provide a clear picture of potential Cash on Cash Return, Cap Rate, and monthly Cash Flow.
Why Cash Flow is King
Cash flow represents the net amount of money moving into or out of a business or asset. In rental real estate, positive cash flow means the rental income exceeds all expenses, including the mortgage, taxes, insurance, and maintenance. Positive cash flow ensures that the property pays for itself and generates passive income for the investor. Conversely, negative cash flow implies that the investor must contribute money monthly to keep the property afloat, which increases risk.
Key Metrics Explained
This calculator breaks down several critical performance indicators that every real estate investor should understand:
Net Operating Income (NOI): This is the total income generated by the property minus all necessary operating expenses (vacancy, management, maintenance, taxes, insurance), but before deducting mortgage payments. NOI is crucial for calculating the Cap Rate.
Cap Rate (Capitalization Rate): Calculated as NOI / Purchase Price. This metric measures the natural rate of return of the property assuming it was bought in cash. It allows you to compare the profitability of different properties regardless of how they are financed.
Cash on Cash Return (CoC): Calculated as Annual Cash Flow / Total Cash Invested. This is arguably the most important metric for leveraged investors. It tells you exactly what return you are getting on the actual dollars you put into the deal (down payment + closing costs).
Understanding the Inputs
To get the most accurate results from this Rental Property Calculator, ensure you are using realistic figures:
Vacancy Rate: No property is occupied 100% of the time. A standard conservative estimate is 5% to 8%, accounting for turnover periods between tenants.
Maintenance & CapEx: Budgeting for repairs is non-negotiable. Setting aside 5-10% of monthly rent ensures you have funds for leaky faucets or larger capital expenditures like a new roof.
Closing Costs: Don't forget the upfront costs of buying! Title fees, inspections, and loan origination fees typically range from 2% to 5% of the purchase price.
How to Interpret Your Results
If your Cash on Cash Return is between 8% and 12%, most investors consider this a solid performing asset, as it generally beats the average stock market return while providing the added benefits of tax depreciation and property appreciation. A negative cash flow is a warning sign that the property is overpriced or the financing terms are too aggressive for the rental market.
Use this calculator to run different scenarios—adjusting your offer price or down payment amount to see how it affects your bottom line. Successful real estate investing starts with accurate analysis.