.calc-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin-bottom: 20px; }
.calc-input-group { display: flex; flex-direction: column; }
.calc-input-group label { font-weight: 600; margin-bottom: 5px; color: #333; font-size: 14px; }
.calc-input-group input { padding: 10px; border: 1px solid #ccc; border-radius: 4px; font-size: 16px; transition: border-color 0.3s; }
.calc-input-group input:focus { border-color: #0073aa; outline: none; }
.calc-section-title { grid-column: 1 / -1; font-size: 18px; font-weight: bold; margin-top: 10px; border-bottom: 2px solid #f0f0f0; padding-bottom: 10px; color: #444; }
.calc-btn { grid-column: 1 / -1; background-color: #0073aa; color: white; border: none; padding: 15px; font-size: 18px; font-weight: bold; border-radius: 4px; cursor: pointer; transition: background-color 0.2s; margin-top: 10px; }
.calc-btn:hover { background-color: #005177; }
.calc-results { margin-top: 30px; background-color: #f9f9f9; padding: 20px; border-radius: 8px; border: 1px solid #eee; display: none; }
.calc-result-row { display: flex; justify-content: space-between; margin-bottom: 10px; padding-bottom: 10px; border-bottom: 1px solid #e0e0e0; }
.calc-result-row:last-child { border-bottom: none; }
.calc-result-label { font-weight: 600; color: #555; }
.calc-result-value { font-weight: bold; color: #333; }
.calc-main-result { background-color: #e6f7ff; padding: 15px; border-radius: 6px; margin-top: 15px; text-align: center; border: 1px solid #b3e0ff; }
.calc-main-result .val { font-size: 24px; color: #0073aa; display: block; margin-top: 5px; }
@media (max-width: 600px) { .calc-grid { grid-template-columns: 1fr; } }
function calculateCashFlow() {
// Get inputs
var price = parseFloat(document.getElementById('rp_price').value);
var downPercent = parseFloat(document.getElementById('rp_down').value);
var rate = parseFloat(document.getElementById('rp_rate').value);
var term = parseFloat(document.getElementById('rp_term').value);
var rent = parseFloat(document.getElementById('rp_rent').value);
var vacancyRate = parseFloat(document.getElementById('rp_vacancy').value);
var mgmtRate = parseFloat(document.getElementById('rp_mgmt').value);
var repairCost = parseFloat(document.getElementById('rp_repair').value);
var annualTax = parseFloat(document.getElementById('rp_tax').value);
var annualIns = parseFloat(document.getElementById('rp_ins').value);
var hoa = parseFloat(document.getElementById('rp_hoa').value);
var closingCosts = parseFloat(document.getElementById('rp_closing').value);
// Validation
if (isNaN(price) || isNaN(downPercent) || isNaN(rate) || isNaN(term) || isNaN(rent)) {
alert("Please enter valid numbers for all fields.");
return;
}
// Loan Calculations
var downPaymentAmount = price * (downPercent / 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;
}
// Expense Calculations
var monthlyVacancyCost = rent * (vacancyRate / 100);
var monthlyMgmtCost = rent * (mgmtRate / 100);
var monthlyTax = annualTax / 12;
var monthlyIns = annualIns / 12;
var totalOperatingExpenses = monthlyVacancyCost + monthlyMgmtCost + repairCost + monthlyTax + monthlyIns + hoa;
var totalMonthlyCosts = monthlyMortgage + totalOperatingExpenses;
// Profit Metrics
var monthlyCashFlow = rent – totalMonthlyCosts;
var annualCashFlow = monthlyCashFlow * 12;
var totalCashInvested = downPaymentAmount + closingCosts;
// NOI (Net Operating Income) = Income – Operating Expenses (No Mortgage)
var monthlyNOI = rent – totalOperatingExpenses;
var annualNOI = monthlyNOI * 12;
// ROI Metrics
var cashOnCash = 0;
if (totalCashInvested > 0) {
cashOnCash = (annualCashFlow / totalCashInvested) * 100;
}
var capRate = 0;
if (price > 0) {
capRate = (annualNOI / price) * 100;
}
// Format Currency
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
minimumFractionDigits: 2
});
// Update UI
document.getElementById('res_gross_rent').innerText = formatter.format(rent);
document.getElementById('res_mortgage').innerText = formatter.format(monthlyMortgage);
document.getElementById('res_opex').innerText = formatter.format(totalOperatingExpenses);
document.getElementById('res_total_costs').innerText = formatter.format(totalMonthlyCosts);
var cfElement = document.getElementById('res_cash_flow');
cfElement.innerText = formatter.format(monthlyCashFlow);
cfElement.style.color = monthlyCashFlow >= 0 ? '#2e7d32' : '#d32f2f';
document.getElementById('res_coc').innerText = cashOnCash.toFixed(2) + "%";
document.getElementById('res_cap_rate').innerText = capRate.toFixed(2) + "%";
document.getElementById('res_noi').innerText = formatter.format(annualNOI);
document.getElementById('rp_result_container').style.display = 'block';
}
Rental Property Cash Flow Calculator
Purchase & Loan Details
Income & Variable Expenses
Fixed Expenses (Annual/Monthly)
Monthly Financial Breakdown
Gross Monthly Rent:
Principal & Interest (Mortgage):
Operating Expenses (Tax, Ins, Maint, etc.):
Total Monthly Costs:
Net Monthly Cash Flow
Investment Metrics
Cash on Cash Return (ROI):
Cap Rate:
Net Operating Income (Annual):
Understanding Your Rental Property Cash Flow
Investing in real estate is one of the most reliable ways to build wealth, but the difference between a successful investment and a financial burden often comes down to one metric: Cash Flow. This Rental Property Cash Flow Calculator is designed to help investors objectively analyze potential deals by accounting for all income and expense variables.
What is Rental Cash Flow?
Cash flow is the net amount of money moving into or out of a rental property business after all expenses have been paid. Positive cash flow means the property generates more income than it costs to own and operate, providing you with passive income. Negative cash flow means you are paying out of pocket to keep the property running.
The basic formula is:
Cash Flow = Gross Rental Income – (Operating Expenses + Debt Service)
Key Metrics Calculated
Beyond simple monthly profit, this tool provides advanced metrics crucial for professional investors:
- NOI (Net Operating Income): This is the annual income generated by the property after deducting all operating expenses but before deducting mortgage payments. It measures the property's raw profitability regardless of financing.
- Cap Rate (Capitalization Rate): Calculated as
NOI / Purchase Price, this percentage allows you to compare the profitability of different properties without considering how they are financed. A higher cap rate generally indicates higher returns (and often higher risk). - Cash-on-Cash Return (CoC): This is arguably the most important metric for investors using leverage. It measures the annual cash flow relative to the actual cash you invested (down payment + closing costs). It answers the question: "What interest rate is my money earning?"
Hidden Expenses Often Overlooked
Many novice investors calculate profitability by simply subtracting the mortgage from the rent. This is a dangerous mistake. To get an accurate picture, you must account for:
- Vacancy Rates: Your property will not be occupied 100% of the time. Factoring in a 5% to 8% vacancy rate creates a buffer for turnover periods.
- Repairs & Maintenance: Roofs leak and toilets break. Setting aside 5% to 10% of monthly rent ensures you have funds available when issues arise.
- Property Management: Even if you plan to self-manage, you should account for the value of your time (typically 8-10% of rent) to see if the deal still makes sense as a passive investment.
- CapEx (Capital Expenditures): These are big-ticket items like replacing a HVAC system or roof. While not monthly, they should be budgeted for annually.
How to Interpret the Results
Positive Cash Flow: If the result is green, the property pays for itself and provides income. Most investors aim for at least $100-$200 per door in pure profit after all conservative expense estimates.
Negative Cash Flow: If the result is red, the property is a liability. While some investors accept negative cash flow in high-appreciation markets, it is a risky strategy that requires significant cash reserves.
Use this calculator to stress-test your deals. What happens if the interest rate goes up by 1%? What if vacancy rises to 10%? Running these scenarios helps you make data-driven investment decisions.