Analyze your real estate investment deal to determine monthly cash flow, Cap Rate, and Cash on Cash Return.
Purchase & Loan Details
Income & Expenses
Analysis Results
Monthly Income (Gross):
Monthly Mortgage (P&I):
Total Monthly Expenses (OpEx):
Net Monthly Cash Flow:
Cash on Cash Return
Cap Rate
Net Operating Income (NOI)
Total Cash Invested
function calculateRental() {
// Get Input Values
var price = parseFloat(document.getElementById('purchasePrice').value);
var downPct = parseFloat(document.getElementById('downPayment').value);
var interest = parseFloat(document.getElementById('interestRate').value);
var term = parseFloat(document.getElementById('loanTerm').value);
var closing = parseFloat(document.getElementById('closingCosts').value) || 0;
var rent = parseFloat(document.getElementById('monthlyRent').value);
var taxYr = parseFloat(document.getElementById('propTax').value);
var insYr = parseFloat(document.getElementById('insurance').value);
var hoaMo = parseFloat(document.getElementById('hoa').value) || 0;
var maintPct = parseFloat(document.getElementById('maintenance').value) || 0;
var vacancyPct = parseFloat(document.getElementById('vacancy').value) || 0;
var capexPct = parseFloat(document.getElementById('capex').value) || 0;
var mgmtPct = parseFloat(document.getElementById('mgmtFee').value) || 0;
// Validate Essential Inputs
if (isNaN(price) || isNaN(downPct) || isNaN(interest) || isNaN(term) || isNaN(rent) || isNaN(taxYr) || isNaN(insYr)) {
alert("Please fill in all required fields (Price, Down Payment, Interest, Term, Rent, Taxes, Insurance).");
return;
}
// Calculations
// 1. Mortgage
var downAmount = price * (downPct / 100);
var loanAmount = price – downAmount;
var monthlyRate = (interest / 100) / 12;
var totalMonths = term * 12;
var monthlyMortgage = 0;
if (interest > 0) {
monthlyMortgage = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, totalMonths)) / (Math.pow(1 + monthlyRate, totalMonths) – 1);
} else {
monthlyMortgage = loanAmount / totalMonths;
}
// 2. Variable Expenses
var vacancyCost = rent * (vacancyPct / 100);
var maintCost = rent * (maintPct / 100);
var capexCost = rent * (capexPct / 100);
var mgmtCost = rent * (mgmtPct / 100);
// 3. Fixed Monthly Expenses (excluding mortgage for NOI)
var taxMo = taxYr / 12;
var insMo = insYr / 12;
var totalOpEx = taxMo + insMo + hoaMo + vacancyCost + maintCost + capexCost + mgmtCost;
var totalExpenses = totalOpEx + monthlyMortgage;
// 4. Metrics
var noiMo = rent – totalOpEx;
var noiYr = noiMo * 12;
var cashFlowMo = noiMo – monthlyMortgage;
var cashFlowYr = cashFlowMo * 12;
var totalCashInvested = downAmount + closing;
var cocReturn = (totalCashInvested > 0) ? (cashFlowYr / totalCashInvested) * 100 : 0;
var capRate = (price > 0) ? (noiYr / price) * 100 : 0;
// Formatters
var fmtMoney = new Intl.NumberFormat('en-US', { style: 'currency', currency: 'USD' });
var fmtPct = new Intl.NumberFormat('en-US', { style: 'percent', minimumFractionDigits: 2 });
// Display Results
document.getElementById('results').style.display = 'block';
document.getElementById('resIncome').innerText = fmtMoney.format(rent);
document.getElementById('resMortgage').innerText = fmtMoney.format(monthlyMortgage);
document.getElementById('resExpenses').innerText = fmtMoney.format(totalOpEx);
var cfEl = document.getElementById('resCashFlow');
cfEl.innerText = fmtMoney.format(cashFlowMo);
cfEl.className = cashFlowMo >= 0 ? "metric-value positive" : "metric-value negative";
var cocEl = document.getElementById('resCoC');
cocEl.innerText = cocReturn.toFixed(2) + "%";
cocEl.className = cocReturn >= 0 ? "metric-value positive" : "metric-value negative";
document.getElementById('resCapRate').innerText = capRate.toFixed(2) + "%";
document.getElementById('resNOI').innerText = fmtMoney.format(noiYr) + "/yr";
document.getElementById('resInvested').innerText = fmtMoney.format(totalCashInvested);
}
About This Rental Property Cash Flow Calculator
Successful real estate investing hinges on the ability to accurately predict cash flow. A property that looks great on the outside might bleed money once you account for vacancy, maintenance, and capital expenditures (CapEx). This Rental Property Cash Flow Calculator helps you evaluate the financial viability of a potential investment property by breaking down income, operating expenses, and debt service.
How to Calculate Rental Cash Flow
Cash flow is the net income remaining after all expenses and mortgage payments are paid. The basic formula used in this calculator is:
While the formula seems simple, the accuracy depends on including all "hidden" expenses:
Vacancy Rate: Properties are rarely 100% occupied. A standard 5-8% deduction ensures you have a buffer for turnover periods.
Maintenance & Repairs: Routine fixes like leaky faucets or painting. Investors typically budget 5-10% of rent.
CapEx (Capital Expenditures): Major replacements like roofs, HVAC systems, or flooring. Budgeting 5-10% monthly saves you from shock costs later.
Property Management: If you hire a professional manager, they typically charge 8-12% of the monthly rent.
Understanding the Key Metrics
This calculator provides several critical metrics to help you compare properties:
1. Net Operating Income (NOI)
NOI calculates the profitability of the property before debt service (mortgage). It is calculated as Gross Income - Operating Expenses. This number is crucial because it represents the property's potential regardless of how you finance it.
2. Cap Rate (Capitalization Rate)
The Cap Rate measures the natural rate of return on the property. It is calculated as (Annual NOI / Purchase Price) × 100. A higher Cap Rate generally indicates a better return, though often associated with higher risk areas. Most investors look for Cap Rates between 5% and 10%.
3. Cash on Cash Return (CoC)
This is arguably the most important metric for investors using leverage (loans). It measures the cash return on the actual cash you invested (Down Payment + Closing Costs). It is calculated as (Annual Cash Flow / Total Cash Invested) × 100. While the stock market averages 7-10%, real estate investors often target 8-12%+ Cash on Cash returns.
Example Scenario
Imagine you buy a property for $200,000 with 20% down ($40,000). You rent it for $2,000/month.
Mortgage (P&I): ~$1,011 (at 6.5% interest)
Taxes & Insurance: ~$350/month
Reserves (Vacancy/Maint/CapEx): ~$300/month
Your total expenses are roughly $1,661. Your monthly cash flow would be $339. This creates a Cash on Cash return of roughly 8-10% depending on closing costs, signaling a solid buy-and-hold investment.