Analyze potential real estate investments to determine monthly cash flow and ROI.
Purchase & Loan Details
Income Details
Recurring Expenses
Investment Analysis
Monthly Cash Flow—
Annual Cash Flow—
Cash on Cash Return (CoC)—
Cap Rate—
Net Operating Income (Monthly)—
Total Monthly Expenses—
function calculateCashFlow() {
// 1. Get Inputs
var price = parseFloat(document.getElementById('rpc-price').value) || 0;
var downPercent = parseFloat(document.getElementById('rpc-down').value) || 0;
var rate = parseFloat(document.getElementById('rpc-rate').value) || 0;
var term = parseFloat(document.getElementById('rpc-term').value) || 0;
var closingCosts = parseFloat(document.getElementById('rpc-closing').value) || 0;
var rent = parseFloat(document.getElementById('rpc-rent').value) || 0;
var otherIncome = parseFloat(document.getElementById('rpc-other').value) || 0;
var vacancyRate = parseFloat(document.getElementById('rpc-vacancy').value) || 0;
var taxAnnual = parseFloat(document.getElementById('rpc-tax').value) || 0;
var insuranceAnnual = parseFloat(document.getElementById('rpc-insurance').value) || 0;
var hoaMonthly = parseFloat(document.getElementById('rpc-hoa').value) || 0;
var maintRate = parseFloat(document.getElementById('rpc-maint').value) || 0;
var capexRate = parseFloat(document.getElementById('rpc-capex').value) || 0;
var mgmtRate = parseFloat(document.getElementById('rpc-mgmt').value) || 0;
// 2. Calculate Mortgage (P&I)
var downPayment = price * (downPercent / 100);
var loanAmount = price – downPayment;
var monthlyRate = (rate / 100) / 12;
var numPayments = term * 12;
var mortgagePayment = 0;
if (loanAmount > 0 && rate > 0 && term > 0) {
mortgagePayment = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, numPayments)) / (Math.pow(1 + monthlyRate, numPayments) – 1);
} else if (loanAmount > 0 && rate === 0) {
mortgagePayment = loanAmount / numPayments;
}
// 3. Calculate Income
var grossMonthlyIncome = rent + otherIncome;
var vacancyCost = grossMonthlyIncome * (vacancyRate / 100);
var effectiveGrossIncome = grossMonthlyIncome – vacancyCost;
// 4. Calculate Operating Expenses
var taxMonthly = taxAnnual / 12;
var insuranceMonthly = insuranceAnnual / 12;
var maintCost = rent * (maintRate / 100);
var capexCost = rent * (capexRate / 100);
var mgmtCost = rent * (mgmtRate / 100);
// Operating Expenses (Excluding Mortgage)
var totalOperatingExpenses = taxMonthly + insuranceMonthly + hoaMonthly + maintCost + capexCost + mgmtCost;
// Total Expenses (Including Mortgage)
var totalMonthlyExpenses = totalOperatingExpenses + mortgagePayment;
// 5. Calculate Metrics
var monthlyNOI = effectiveGrossIncome – totalOperatingExpenses;
var annualNOI = monthlyNOI * 12;
var monthlyCashFlow = monthlyNOI – mortgagePayment;
var annualCashFlow = monthlyCashFlow * 12;
var totalCashInvested = downPayment + closingCosts;
var cocReturn = 0;
if (totalCashInvested > 0) {
cocReturn = (annualCashFlow / totalCashInvested) * 100;
}
var capRate = 0;
if (price > 0) {
capRate = (annualNOI / price) * 100;
}
// 6. Format and Display Results
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
minimumFractionDigits: 2
});
var percentFormatter = new Intl.NumberFormat('en-US', {
style: 'percent',
minimumFractionDigits: 2,
maximumFractionDigits: 2
});
// Display
document.getElementById('rpc-results').style.display = 'block';
var cfElement = document.getElementById('res-cashflow');
cfElement.innerHTML = formatter.format(monthlyCashFlow);
cfElement.className = monthlyCashFlow >= 0 ? "rpc-result-value rpc-highlight" : "rpc-result-value rpc-highlight-neg";
document.getElementById('res-annual-cashflow').innerHTML = formatter.format(annualCashFlow);
var cocElement = document.getElementById('res-coc');
cocElement.innerHTML = cocReturn.toFixed(2) + "%";
cocElement.className = cocReturn >= 0 ? "rpc-result-value rpc-highlight" : "rpc-result-value rpc-highlight-neg";
document.getElementById('res-caprate').innerHTML = capRate.toFixed(2) + "%";
document.getElementById('res-noi').innerHTML = formatter.format(monthlyNOI);
document.getElementById('res-expenses').innerHTML = formatter.format(totalMonthlyExpenses);
}
Mastering Real Estate Investment with Cash Flow Analysis
Investing in rental properties is one of the most reliable ways to build long-term wealth. However, the difference between a profitable asset and a financial burden often comes down to the numbers. This Rental Property Cash Flow Calculator helps you accurately evaluate the potential profitability of an investment property before you sign on the dotted line.
Why Cash Flow is King
Cash flow represents the net income from a real estate investment after mortgage payments and operating expenses have been made. Positive cash flow means the property is putting money into your pocket every month, while negative cash flow means you are paying out of pocket to hold the asset.
While appreciation (the increase in property value over time) is important, cash flow is the lifeblood of a rental business. It provides the liquidity needed to handle repairs, vacancies, and eventually, the capital to purchase more properties.
Understanding Key Metrics
This calculator provides several critical metrics to help you judge a deal:
Net Operating Income (NOI): This is your total income minus operating expenses, excluding mortgage payments. It represents the inherent profitability of the property itself, regardless of financing.
Cash on Cash Return (CoC): This measures the annual return on the actual cash you invested (down payment + closing costs). It is a crucial metric for comparing real estate returns against other investment vehicles like stocks or bonds.
Cap Rate (Capitalization Rate): Calculated by dividing NOI by the property's purchase price. Cap rate helps compare the profitability of similar properties in the same market, assuming an all-cash purchase.
How to Use This Calculator
To get the most accurate results, ensure you input realistic numbers for all expense categories:
Purchase & Loan: Enter the price and your financing terms. A higher interest rate or lower down payment will significantly increase your monthly mortgage obligation.
Vacancy Rate: No property is occupied 100% of the time. A standard conservative estimate is 5-8%, depending on the local market.
Maintenance & CapEx: Many new investors make the mistake of ignoring maintenance. Setting aside 10-15% of rent for routine repairs and major capital expenditures (like a new roof) is prudent.
Management Fees: Even if you plan to self-manage, it is wise to factor in a management fee (typically 8-10%) to account for the value of your time or future professional management.
Interpreting Your Results
If your calculation shows negative cash flow, re-evaluate your offer price or financing strategy. Sometimes, a deal only makes sense with a larger down payment or if you can negotiate a lower purchase price. Use this tool to run "what-if" scenarios until you find the numbers that meet your investment goals.