#rental-calculator-wrapper {
font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
max-width: 800px;
margin: 0 auto;
background: #ffffff;
border: 1px solid #e0e0e0;
border-radius: 8px;
padding: 20px;
box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}
#rental-calculator-wrapper h2 {
color: #2c3e50;
text-align: center;
margin-bottom: 25px;
font-size: 24px;
}
.calc-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
}
@media (max-width: 600px) {
.calc-grid {
grid-template-columns: 1fr;
}
}
.input-group {
margin-bottom: 15px;
}
.input-group label {
display: block;
margin-bottom: 5px;
font-weight: 600;
color: #555;
font-size: 14px;
}
.input-group input {
width: 100%;
padding: 10px;
border: 1px solid #ddd;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
.input-group input:focus {
border-color: #3498db;
outline: none;
box-shadow: 0 0 5px rgba(52,152,219,0.3);
}
.section-title {
grid-column: 1 / -1;
font-size: 18px;
color: #34495e;
border-bottom: 2px solid #ecf0f1;
padding-bottom: 10px;
margin-top: 10px;
margin-bottom: 15px;
}
button.calc-btn {
grid-column: 1 / -1;
background-color: #27ae60;
color: white;
border: none;
padding: 15px;
font-size: 18px;
border-radius: 5px;
cursor: pointer;
transition: background 0.3s;
margin-top: 10px;
width: 100%;
font-weight: bold;
}
button.calc-btn:hover {
background-color: #219150;
}
#results-area {
grid-column: 1 / -1;
background: #f8f9fa;
border: 1px solid #dee2e6;
padding: 20px;
border-radius: 5px;
margin-top: 20px;
display: none;
}
.result-row {
display: flex;
justify-content: space-between;
padding: 10px 0;
border-bottom: 1px solid #e9ecef;
}
.result-row:last-child {
border-bottom: none;
}
.result-label {
color: #666;
font-weight: 500;
}
.result-value {
font-weight: bold;
color: #2c3e50;
}
.positive {
color: #27ae60;
}
.negative {
color: #c0392b;
}
.highlight {
font-size: 1.2em;
}
.seo-content {
margin-top: 40px;
line-height: 1.6;
color: #444;
}
.seo-content h3 {
color: #2c3e50;
margin-top: 25px;
}
.seo-content p {
margin-bottom: 15px;
}
.seo-content ul {
margin-bottom: 15px;
padding-left: 20px;
}
function calculateCashFlow() {
// Get Input Values
var price = parseFloat(document.getElementById('purchasePrice').value);
var downPerc = parseFloat(document.getElementById('downPayment').value);
var interest = parseFloat(document.getElementById('interestRate').value);
var termYears = parseFloat(document.getElementById('loanTerm').value);
var rent = parseFloat(document.getElementById('monthlyRent').value);
var annualTax = parseFloat(document.getElementById('propertyTax').value);
var annualIns = parseFloat(document.getElementById('insurance').value);
var maintPerc = parseFloat(document.getElementById('maintenance').value);
var vacPerc = parseFloat(document.getElementById('vacancy').value);
var mgmtPerc = parseFloat(document.getElementById('mgmtFee').value);
// Validation
if (isNaN(price) || isNaN(rent) || isNaN(interest) || isNaN(termYears)) {
alert("Please enter valid numbers for all fields.");
return;
}
// Calculations
var downPaymentAmt = price * (downPerc / 100);
var loanAmount = price – downPaymentAmt;
// Mortgage Payment (P&I)
// M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
var monthlyRate = (interest / 100) / 12;
var numPayments = termYears * 12;
var monthlyMortgage = 0;
if (interest === 0) {
monthlyMortgage = loanAmount / numPayments;
} else {
monthlyMortgage = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, numPayments)) / (Math.pow(1 + monthlyRate, numPayments) – 1);
}
// Monthly Expenses
var monthlyTax = annualTax / 12;
var monthlyIns = annualIns / 12;
var monthlyMaint = rent * (maintPerc / 100);
var monthlyVac = rent * (vacPerc / 100);
var monthlyMgmt = rent * (mgmtPerc / 100);
var totalMonthlyExpenses = monthlyMortgage + monthlyTax + monthlyIns + monthlyMaint + monthlyVac + monthlyMgmt;
var monthlyCashFlow = rent – totalMonthlyExpenses;
var annualCashFlow = monthlyCashFlow * 12;
// Cash on Cash Return
// (Annual Cash Flow / Total Cash Invested) * 100
// Assuming closing costs are roughly 2% of price for estimation if not specified,
// but for strict calculator we stick to Down Payment to avoid hidden assumptions.
var totalCashInvested = downPaymentAmt;
var cocReturn = (annualCashFlow / totalCashInvested) * 100;
// Cap Rate
// (Net Operating Income / Purchase Price) * 100
// NOI = Rent – Operating Expenses (Tax, Ins, Maint, Vac, Mgmt) -> EXCLUDING Mortgage
var monthlyOpExpenses = monthlyTax + monthlyIns + monthlyMaint + monthlyVac + monthlyMgmt;
var annualNOI = (rent – monthlyOpExpenses) * 12;
var capRate = (annualNOI / price) * 100;
// Display Results
document.getElementById('results-area').style.display = 'block';
document.getElementById('resMortgage').innerText = formatCurrency(monthlyMortgage);
document.getElementById('resExpenses').innerText = formatCurrency(totalMonthlyExpenses);
var cfEl = document.getElementById('resCashFlow');
cfEl.innerText = formatCurrency(monthlyCashFlow);
if (monthlyCashFlow >= 0) {
cfEl.className = "result-value highlight positive";
} else {
cfEl.className = "result-value highlight negative";
}
document.getElementById('resCoC').innerText = cocReturn.toFixed(2) + "%";
document.getElementById('resCapRate').innerText = capRate.toFixed(2) + "%";
}
function formatCurrency(num) {
return "$" + num.toFixed(2).replace(/\d(?=(\d{3})+\.)/g, '$&,');
}
Rental Property Cash Flow Calculator
Purchase & Loan Details
Income & Expenses
Monthly Mortgage P&I:
$0.00
Total Monthly Expenses:
$0.00
Monthly Cash Flow:
$0.00
Cash on Cash Return (ROI):
0.00%
Cap Rate:
0.00%
Understanding Rental Property Cash Flow
Investing in real estate requires more than just buying a property and collecting rent. To ensure your investment is profitable, you must accurately calculate your Cash Flow. This is the net amount of money left in your pocket each month after all operating expenses and mortgage payments are made. A positive cash flow indicates a healthy investment that generates passive income.
Key Metrics Explained
- Cash on Cash Return (CoC): This metric measures the annual return on the actual cash you invested (down payment + closing costs). It is a critical indicator of how hard your money is working for you.
- Cap Rate (Capitalization Rate): This measures the rate of return on a rental investment property based on the income that the property is expected to generate, regardless of financing. It helps compare properties purely on their performance.
- Vacancy & Maintenance: New investors often forget to account for these. Always budget a percentage of rent for when the unit is empty (vacancy) and for repairs (maintenance/CapEx).
How to Improve Your ROI
If the calculator shows a negative cash flow or low ROI, consider these adjustments: negotiating a lower purchase price to reduce the mortgage, increasing the down payment to lower monthly debt service, or looking for ways to increase rental income through value-add renovations. Accurate numbers are the foundation of successful real estate investing.