#rental-property-calculator-wrapper .calc-container {
background: #f9fbfd;
border: 1px solid #e1e4e8;
border-radius: 8px;
padding: 30px;
box-shadow: 0 4px 6px rgba(0,0,0,0.05);
margin-bottom: 40px;
}
#rental-property-calculator-wrapper h2 {
margin-top: 0;
color: #2c3e50;
font-size: 24px;
margin-bottom: 20px;
text-align: center;
}
#rental-property-calculator-wrapper .input-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
}
@media (max-width: 600px) {
#rental-property-calculator-wrapper .input-grid {
grid-template-columns: 1fr;
}
}
#rental-property-calculator-wrapper .form-group {
margin-bottom: 15px;
}
#rental-property-calculator-wrapper label {
display: block;
font-weight: 600;
margin-bottom: 5px;
font-size: 14px;
color: #4a5568;
}
#rental-property-calculator-wrapper input[type="number"] {
width: 100%;
padding: 10px;
border: 1px solid #cbd5e0;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
#rental-property-calculator-wrapper .section-title {
grid-column: 1 / -1;
font-weight: bold;
color: #2b6cb0;
border-bottom: 2px solid #e2e8f0;
padding-bottom: 5px;
margin-top: 10px;
}
#rental-property-calculator-wrapper .btn-calc {
background-color: #2b6cb0;
color: white;
border: none;
padding: 15px 30px;
font-size: 18px;
font-weight: bold;
border-radius: 4px;
cursor: pointer;
width: 100%;
margin-top: 20px;
transition: background 0.2s;
}
#rental-property-calculator-wrapper .btn-calc:hover {
background-color: #2c5282;
}
#rental-property-calculator-wrapper .results-box {
background: #fff;
border: 1px solid #e2e8f0;
border-radius: 6px;
padding: 20px;
margin-top: 30px;
display: none;
}
#rental-property-calculator-wrapper .result-row {
display: flex;
justify-content: space-between;
align-items: center;
padding: 10px 0;
border-bottom: 1px solid #edf2f7;
}
#rental-property-calculator-wrapper .result-row:last-child {
border-bottom: none;
}
#rental-property-calculator-wrapper .result-label {
font-weight: 500;
color: #718096;
}
#rental-property-calculator-wrapper .result-value {
font-weight: bold;
font-size: 18px;
color: #2d3748;
}
#rental-property-calculator-wrapper .highlight {
color: #38a169;
font-size: 22px;
}
#rental-property-calculator-wrapper .neg-highlight {
color: #e53e3e;
font-size: 22px;
}
#rental-property-calculator-wrapper .article-content h3 {
color: #2d3748;
margin-top: 30px;
}
#rental-property-calculator-wrapper .article-content p {
line-height: 1.6;
margin-bottom: 15px;
color: #4a5568;
}
#rental-property-calculator-wrapper .article-content ul {
margin-bottom: 15px;
padding-left: 20px;
line-height: 1.6;
}
function calculateRentalCashFlow() {
// Get Input Values
var price = parseFloat(document.getElementById('purchasePrice').value) || 0;
var down = parseFloat(document.getElementById('downPayment').value) || 0;
var interestRate = parseFloat(document.getElementById('interestRate').value) || 0;
var loanTerm = parseFloat(document.getElementById('loanTerm').value) || 0;
var rent = parseFloat(document.getElementById('monthlyRent').value) || 0;
var taxAnnual = parseFloat(document.getElementById('propertyTax').value) || 0;
var insuranceAnnual = parseFloat(document.getElementById('insurance').value) || 0;
var hoa = parseFloat(document.getElementById('hoa').value) || 0;
var maintenance = parseFloat(document.getElementById('maintenance').value) || 0;
var vacancyRate = parseFloat(document.getElementById('vacancyRate').value) || 0;
// 1. Calculate Mortgage Payment
var loanAmount = price – down;
var monthlyInterest = (interestRate / 100) / 12;
var totalPayments = loanTerm * 12;
var monthlyMortgage = 0;
if (loanAmount > 0 && interestRate > 0 && loanTerm > 0) {
// Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
monthlyMortgage = loanAmount * (monthlyInterest * Math.pow(1 + monthlyInterest, totalPayments)) / (Math.pow(1 + monthlyInterest, totalPayments) – 1);
} else if (loanAmount > 0 && interestRate === 0) {
monthlyMortgage = loanAmount / totalPayments;
}
// 2. Calculate Operating Expenses (Monthly)
var taxMonthly = taxAnnual / 12;
var insuranceMonthly = insuranceAnnual / 12;
var vacancyCost = rent * (vacancyRate / 100);
// Total Operating Expenses (Excluding Mortgage)
var monthlyOperatingExpenses = taxMonthly + insuranceMonthly + hoa + maintenance + vacancyCost;
// 3. Effective Gross Income
var effectiveIncome = rent – vacancyCost;
// Note: Vacancy is usually treated as a deduction from Gross Potential Income to get Effective Gross Income,
// but for expense summing, we often group it. To keep math clean for NOI:
// NOI = (Gross Rent – Vacancy Loss) – (Taxes + Ins + HOA + Maint)
var monthlyNOI = (rent – vacancyCost) – (taxMonthly + insuranceMonthly + hoa + maintenance);
var annualNOI = monthlyNOI * 12;
// 4. Cash Flow
var totalMonthlyExpenses = monthlyMortgage + monthlyOperatingExpenses;
// Note: We already accounted for vacancy in 'monthlyOperatingExpenses' variable above?
// Wait, let's look at the variable again.
// monthlyOperatingExpenses = tax + ins + hoa + maint + vacancy.
// Cash Flow = Rent – (OperatingExpenses + Mortgage).
// This is correct: Rent – Vacancy – HardCosts – Mortgage.
var monthlyCashFlow = rent – totalMonthlyExpenses;
var annualCashFlow = monthlyCashFlow * 12;
// 5. Returns
var capRate = 0;
if (price > 0) {
capRate = (annualNOI / price) * 100;
}
var cashOnCash = 0;
if (down > 0) {
cashOnCash = (annualCashFlow / down) * 100;
}
// Display Results
document.getElementById('displayMortgage').innerText = "$" + monthlyMortgage.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
// For display expenses, we usually show the cash outflow (excluding vacancy "loss" which is unrealized, but including hard costs).
// However, strictly speaking, vacancy is lost income.
// Let's display "Total Out-of-Pocket Expenses" (Mortgage + Taxes + Ins + HOA + Maint).
var outOfPocketExpenses = monthlyMortgage + taxMonthly + insuranceMonthly + hoa + maintenance;
document.getElementById('displayExpenses').innerText = "$" + outOfPocketExpenses.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('displayNOI').innerText = "$" + monthlyNOI.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
var cashFlowEl = document.getElementById('displayCashFlow');
cashFlowEl.innerText = "$" + monthlyCashFlow.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
// Style changes for positive/negative cashflow
if (monthlyCashFlow >= 0) {
cashFlowEl.className = "result-value highlight";
} else {
cashFlowEl.className = "result-value neg-highlight";
}
document.getElementById('displayCapRate').innerText = capRate.toFixed(2) + "%";
var cocEl = document.getElementById('displayCoC');
cocEl.innerText = cashOnCash.toFixed(2) + "%";
if (cashOnCash < 0) {
cocEl.style.color = "#e53e3e";
} else {
cocEl.style.color = "#2d3748";
}
// Show results div
document.getElementById('results').style.display = 'block';
}
Rental Property Cash Flow Calculator
Purchase & Loan Info
Income & Expenses
Investment Analysis
Monthly Mortgage (P&I):
$0.00
Total Monthly Expenses:
$0.00
Net Operating Income (NOI – Monthly):
$0.00
Monthly Cash Flow:
$0.00
Cap Rate:
0.00%
Cash on Cash Return:
0.00%
Guide to Analyzing Rental Property Cash Flow
Investing in real estate is one of the most reliable ways to build wealth, but not every property is a good deal. The difference between a profitable asset and a financial liability lies in the numbers. This Rental Property Cash Flow Calculator helps you evaluate the potential profitability of a real estate investment by breaking down income, expenses, and key return metrics.
What is Cash Flow in Real Estate?
Cash flow is the net amount of cash moving in and out of a business. In rental property terms, it is the money remaining after all operating expenses and mortgage payments have been made from the collected rental income.
- Positive Cash Flow: You earn more in rent than you spend on expenses. This is the goal for most buy-and-hold investors.
- Negative Cash Flow: The property costs you money to hold every month. Investors usually avoid this unless they are banking on significant appreciation.
Key Metrics Explained
Our calculator provides several vital metrics to help you make an informed decision:
1. Net Operating Income (NOI)
NOI is calculated by subtracting all operating expenses (taxes, insurance, maintenance, HOA, vacancy) from the total income. Crucially, NOI excludes mortgage payments. It measures the profitability of the property itself, regardless of how it is financed.
2. Cap Rate (Capitalization Rate)
The Cap Rate is the ratio of Net Operating Income to the property's asset value (Purchase Price). It is calculated as (NOI / Purchase Price) × 100. A higher cap rate generally indicates a higher potential return, though often with higher risk. It allows you to compare properties with different price points directly.
3. Cash on Cash Return (CoC)
This is arguably the most important metric for investors using leverage (loans). It measures the annual cash flow relative to the total cash invested (Down Payment). Calculated as (Annual Cash Flow / Total Cash Invested) × 100, it tells you how hard your actual dollars are working for you.
How to Estimate Expenses
Accurate calculation requires realistic expense estimates. Do not underestimate costs. Common pitfalls include:
- Vacancy Rate: Always assume the property will sit empty for a portion of the year. A standard safe estimate is 5-8%.
- Maintenance: Even new homes need repairs. Budgeting 1% of the property value per year or 10% of the rent is a prudent safeguard.
- CapEx (Capital Expenditures): Major items like roofs and HVAC systems eventually need replacement. Smart investors set aside reserves monthly for these future costs.