Investment Property Cash Flow Calculator
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Investment Analysis
Est. Monthly Cash Flow
$0.00
Monthly Financial Breakdown
| Rental Income |
$0.00 |
| Mortgage (P&I) |
$0.00 |
| Property Tax |
$0.00 |
| Insurance |
$0.00 |
| HOA & Fees |
$0.00 |
| Maintenance |
$0.00 |
| Vacancy Reserve |
$0.00 |
| Management Fees |
$0.00 |
| Total Expenses |
$0.00 |
| Net Operating Income (NOI) |
$0.00 |
function calculateROI() {
// 1. Get Inputs
var price = parseFloat(document.getElementById('purchasePrice').value) || 0;
var downPercent = parseFloat(document.getElementById('downPaymentPercent').value) || 0;
var interestRate = parseFloat(document.getElementById('interestRate').value) || 0;
var years = parseFloat(document.getElementById('loanTerm').value) || 0;
var closingCosts = parseFloat(document.getElementById('closingCosts').value) || 0;
var monthlyRent = parseFloat(document.getElementById('monthlyRent').value) || 0;
var annualTax = parseFloat(document.getElementById('propertyTax').value) || 0;
var annualInsurance = parseFloat(document.getElementById('insurance').value) || 0;
var hoa = parseFloat(document.getElementById('hoaFees').value) || 0;
var maintenance = parseFloat(document.getElementById('maintenance').value) || 0;
var vacancyRate = parseFloat(document.getElementById('vacancyRate').value) || 0;
var managementFeeRate = parseFloat(document.getElementById('managementFee').value) || 0;
// 2. Calculations
// Loan Details
var downPaymentAmount = price * (downPercent / 100);
var loanAmount = price – downPaymentAmount;
var totalCashInvested = downPaymentAmount + closingCosts;
// Mortgage Payment (P&I)
var monthlyMortgage = 0;
if (loanAmount > 0 && interestRate > 0 && years > 0) {
var monthlyRate = (interestRate / 100) / 12;
var numPayments = years * 12;
monthlyMortgage = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, numPayments)) / (Math.pow(1 + monthlyRate, numPayments) – 1);
}
// Variable Monthly Expenses
var monthlyTax = annualTax / 12;
var monthlyInsurance = annualInsurance / 12;
var vacancyCost = monthlyRent * (vacancyRate / 100);
var managementCost = monthlyRent * (managementFeeRate / 100);
// Operating Expenses (Excluding Mortgage)
var operatingExpenses = monthlyTax + monthlyInsurance + hoa + maintenance + vacancyCost + managementCost;
// Total Expenses
var totalExpenses = operatingExpenses + monthlyMortgage;
// Cash Flow
var monthlyCashFlow = monthlyRent – totalExpenses;
var annualCashFlow = monthlyCashFlow * 12;
// NOI (Net Operating Income) – Annualized
// NOI is Income minus Operating Expenses (excluding debt service)
var annualNOI = (monthlyRent * 12) – (operatingExpenses * 12);
var monthlyNOI = monthlyRent – operatingExpenses;
// Returns
var capRate = 0;
if (price > 0) {
capRate = (annualNOI / price) * 100;
}
var cocReturn = 0;
if (totalCashInvested > 0) {
cocReturn = (annualCashFlow / totalCashInvested) * 100;
}
// 3. Update DOM
// Formatter
var currencyParams = { style: 'currency', currency: 'USD' };
var percentParams = { minimumFractionDigits: 2, maximumFractionDigits: 2 };
// Main Results
var cfElement = document.getElementById('monthlyCashFlow');
cfElement.innerText = monthlyCashFlow.toLocaleString('en-US', currencyParams);
if(monthlyCashFlow >= 0) {
cfElement.className = "result-value positive";
} else {
cfElement.className = "result-value negative";
}
document.getElementById('cocReturn').innerText = cocReturn.toLocaleString('en-US', percentParams) + "%";
document.getElementById('capRate').innerText = capRate.toLocaleString('en-US', percentParams) + "%";
// Table Breakdown
document.getElementById('displayIncome').innerText = monthlyRent.toLocaleString('en-US', currencyParams);
document.getElementById('displayMortgage').innerText = "(" + monthlyMortgage.toLocaleString('en-US', currencyParams) + ")";
document.getElementById('displayTax').innerText = "(" + monthlyTax.toLocaleString('en-US', currencyParams) + ")";
document.getElementById('displayInsurance').innerText = "(" + monthlyInsurance.toLocaleString('en-US', currencyParams) + ")";
document.getElementById('displayHOA').innerText = "(" + hoa.toLocaleString('en-US', currencyParams) + ")";
document.getElementById('displayMaintenance').innerText = "(" + maintenance.toLocaleString('en-US', currencyParams) + ")";
document.getElementById('displayVacancy').innerText = "(" + vacancyCost.toLocaleString('en-US', currencyParams) + ")";
document.getElementById('displayManagement').innerText = "(" + managementCost.toLocaleString('en-US', currencyParams) + ")";
document.getElementById('displayTotalExpenses').innerText = "(" + totalExpenses.toLocaleString('en-US', currencyParams) + ")";
document.getElementById('displayNOI_monthly').innerText = monthlyNOI.toLocaleString('en-US', currencyParams);
}
// Initial Calculation on Load
window.onload = function() {
calculateROI();
};
Understanding Investment Property Cash Flow
Calculating the potential return on a real estate investment is crucial before signing any purchase agreement. A Rental Property Cash Flow Calculator helps investors analyze a deal by breaking down income, operating expenses, and debt service to reveal the true profitability of a property.
Expert Tip: Always overestimate your expenses and underestimate your income when running the numbers. This "stress test" ensures your investment remains profitable even if maintenance costs rise or vacancy rates increase.
Key Metrics Explained
1. Monthly Cash Flow
This is the profit you pocket every month after all bills are paid. It is calculated as:
- Formula: Total Rental Income – Total Monthly Expenses (Mortgage + Operating Costs)
Positive cash flow ensures the property pays for itself and provides passive income. Negative cash flow implies you must contribute money monthly to keep the asset.
2. Cash on Cash Return (CoC)
This metric measures the annual return on the actual cash you invested (Down Payment + Closing Costs), rather than the total loan amount. It is one of the most important metrics for leverage-based investing.
- Formula: (Annual Pre-Tax Cash Flow / Total Cash Invested) * 100
- Example: If you invest $50,000 cash and receive $5,000 in annual cash flow, your CoC return is 10%.
3. Cap Rate (Capitalization Rate)
Cap Rate measures the property's natural rate of return assuming you paid all cash (no mortgage). It helps compare the profitability of similar properties regardless of financing.
- Formula: (Net Operating Income / Purchase Price) * 100
Net Operating Income (NOI) includes all income minus operating expenses (taxes, insurance, maintenance) but excludes mortgage payments.
Hidden Costs to Watch For
Many novice investors fail because they only calculate Mortgage vs. Rent. To get an accurate picture, you must account for:
- Vacancy Rate: You won't have a tenant 12 months a year forever. A standard 5-8% reserve is prudent.
- Maintenance & CapEx: Roofs leak and toilets break. Setting aside 5-10% of rent for repairs is essential.
- Property Management: Even if you self-manage now, calculating a 8-10% management fee helps you see if the deal still works if you hire a manager later.
How to Use This Calculator
- Property Details: Enter the purchase price and your loan terms. Don't forget closing costs, which affect your "Cash on Cash" return.
- Income: Enter the gross monthly rent.
- Expenses: Be realistic with taxes, insurance, and HOA fees. Use the percentage fields to set aside reserves for vacancy and repairs.
- Analyze: Review the "Monthly Cash Flow" and "Cash on Cash Return" to determine if the asset meets your investment goals.