body {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
line-height: 1.6;
color: #333;
margin: 0;
padding: 20px;
}
.calculator-wrapper {
max-width: 800px;
margin: 0 auto;
border: 1px solid #e0e0e0;
border-radius: 8px;
box-shadow: 0 4px 12px rgba(0,0,0,0.05);
background: #fff;
padding: 30px;
}
.calc-header {
text-align: center;
margin-bottom: 30px;
border-bottom: 2px solid #f0f0f0;
padding-bottom: 20px;
}
.calc-header h2 {
color: #2c3e50;
margin: 0;
font-size: 28px;
}
.input-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
}
@media (max-width: 600px) {
.input-grid {
grid-template-columns: 1fr;
}
}
.input-group {
margin-bottom: 15px;
}
.input-group label {
display: block;
margin-bottom: 8px;
font-weight: 600;
font-size: 14px;
color: #555;
}
.input-group input {
width: 100%;
padding: 12px;
border: 1px solid #ddd;
border-radius: 6px;
font-size: 16px;
box-sizing: border-box; /* Critical for padding */
transition: border-color 0.3s;
}
.input-group input:focus {
border-color: #3498db;
outline: none;
}
.calc-btn-container {
text-align: center;
margin-top: 20px;
}
button.calc-btn {
background-color: #2ecc71;
color: white;
border: none;
padding: 15px 40px;
font-size: 18px;
font-weight: bold;
border-radius: 6px;
cursor: pointer;
transition: background-color 0.3s;
}
button.calc-btn:hover {
background-color: #27ae60;
}
.results-section {
margin-top: 30px;
background-color: #f8f9fa;
padding: 20px;
border-radius: 8px;
display: none; /* Hidden by default */
border: 1px solid #e9ecef;
}
.result-row {
display: flex;
justify-content: space-between;
margin-bottom: 15px;
padding-bottom: 10px;
border-bottom: 1px solid #e0e0e0;
}
.result-row:last-child {
border-bottom: none;
margin-bottom: 0;
}
.result-label {
font-weight: 600;
color: #555;
}
.result-value {
font-weight: bold;
color: #2c3e50;
font-size: 18px;
}
.highlight-result {
color: #27ae60;
font-size: 22px;
}
.negative {
color: #e74c3c;
}
.article-section {
max-width: 800px;
margin: 50px auto;
padding: 0 20px;
}
.article-section h2 {
color: #2c3e50;
margin-top: 40px;
}
.article-section h3 {
color: #34495e;
margin-top: 25px;
}
.article-section p, .article-section li {
color: #555;
font-size: 17px;
}
.info-box {
background: #e8f4fd;
border-left: 4px solid #3498db;
padding: 15px;
margin: 20px 0;
}
function calculateRental() {
// 1. Get Input Values
var price = parseFloat(document.getElementById('propPrice').value) || 0;
var downPmt = parseFloat(document.getElementById('downPayment').value) || 0;
var rate = parseFloat(document.getElementById('interestRate').value) || 0;
var termYears = parseFloat(document.getElementById('loanTerm').value) || 0;
var rent = parseFloat(document.getElementById('monthlyRent').value) || 0;
var vacancyPct = parseFloat(document.getElementById('vacancyRate').value) || 0;
var opEx = parseFloat(document.getElementById('monthlyOpEx').value) || 0;
var closing = parseFloat(document.getElementById('closingCosts').value) || 0;
// 2. Validate essential inputs to prevent errors
if (price <= 0 || termYears 0) {
cocReturn = (annualCashFlow / totalInitialInvestment) * 100;
}
var capRate = 0;
if (price > 0) {
capRate = (annualNOI / price) * 100;
}
// 9. Display Results
document.getElementById('results').style.display = 'block';
// Helper for currency formatting
var fmtCurr = new Intl.NumberFormat('en-US', { style: 'currency', currency: 'USD' });
document.getElementById('dispMortgage').innerText = fmtCurr.format(monthlyMortgage);
document.getElementById('dispTotalExp').innerText = fmtCurr.format(totalMonthlyExpenses);
document.getElementById('dispNOI').innerText = fmtCurr.format(monthlyNOI);
var cfElem = document.getElementById('dispCashFlow');
cfElem.innerText = fmtCurr.format(monthlyCashFlow);
cfElem.className = monthlyCashFlow >= 0 ? "result-value highlight-result" : "result-value highlight-result negative";
var annCfElem = document.getElementById('dispAnnualCashFlow');
annCfElem.innerText = fmtCurr.format(annualCashFlow);
annCfElem.className = annualCashFlow >= 0 ? "result-value" : "result-value negative";
var cocElem = document.getElementById('dispCoC');
cocElem.innerText = cocReturn.toFixed(2) + "%";
cocElem.className = cocReturn >= 0 ? "result-value highlight-result" : "result-value highlight-result negative";
document.getElementById('dispCapRate').innerText = capRate.toFixed(2) + "%";
}
Understanding Rental Property Cash Flow Analysis
Investing in real estate is a numbers game. Whether you are a seasoned investor looking at a multi-family unit or a beginner purchasing your first single-family rental, understanding the math behind the property is crucial for long-term success. This Rental Property Cash Flow Calculator helps you evaluate the profitability of a potential investment by breaking down income, expenses, and return on investment (ROI) metrics.
What is Cash Flow?
Cash flow is the net amount of cash moving into and out of a business—in this case, your rental property. It is calculated by taking your total monthly rental income and subtracting all expenses, including the mortgage payment, taxes, insurance, and maintenance costs.
Formula:
Cash Flow = Total Income – (Operating Expenses + Debt Service)
Positive Cash Flow: This means the property generates more income than it costs to own. This is the primary goal for most buy-and-hold investors.
Negative Cash Flow: This means you are losing money every month to keep the property. While some investors accept this in hopes of high appreciation, it is generally considered risky.
Key Metrics Explained
1. Net Operating Income (NOI)
NOI is a calculation used to analyze the profitability of income-generating real estate investments. It equals all revenue from the property, minus all reasonably necessary operating expenses. Notably, NOI excludes mortgage payments (debt service). It represents the raw earning potential of the asset itself, regardless of how it is financed.
2. Cash on Cash Return (CoC)
Cash on Cash Return is perhaps the most important metric for investors using leverage (loans). It measures the annual return you made on the actual cash you invested (Down Payment + Closing Costs), expressed as a percentage.
- A CoC of 8-12% is often considered a solid return in many markets.
- It allows you to compare real estate returns against other investments like stocks or bonds.
3. Cap Rate (Capitalization Rate)
The Cap Rate indicates the rate of return that is expected to be generated on a real estate investment property. It is calculated by dividing the Net Operating Income (NOI) by the property asset value (Purchase Price). Since it doesn't account for the mortgage, it is useful for comparing properties directly against one another, regardless of financing.
Real World Example
Imagine you are buying a property for $200,000. You put $40,000 (20%) down and pay $5,000 in closing costs. Your total cash invested is $45,000.
- Rental Income: $2,000/month
- Mortgage Payment: $1,000/month
- Taxes/Insurance/Repairs: $600/month
Your Monthly Cash Flow would be: $2,000 – $1,600 = $400/month ($4,800/year).
Your Cash on Cash Return would be: $4,800 / $45,000 = 10.66%.
Using the calculator above allows you to tweak variables like vacancy rates (often estimated at 5-10%) and repair budgets to see how sensitive your investment is to market changes.
Why Include Vacancy Rates?
No property is occupied 100% of the time. Tenants move out, and it takes time to clean, repair, and market the unit. A vacancy rate of 5% assumes the property will sit empty for about 18 days a year. Omitting this from your calculation can lead to overestimating your profit.