.rp-calculator-wrapper {
max-width: 800px;
margin: 20px auto;
font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
background: #ffffff;
border: 1px solid #e0e0e0;
border-radius: 8px;
box-shadow: 0 4px 12px rgba(0,0,0,0.05);
padding: 0;
overflow: hidden;
}
.rp-calc-header {
background: #2c3e50;
color: #fff;
padding: 20px;
text-align: center;
}
.rp-calc-header h2 {
margin: 0;
font-size: 24px;
font-weight: 600;
}
.rp-calc-body {
padding: 25px;
display: flex;
flex-wrap: wrap;
gap: 30px;
}
.rp-input-section {
flex: 1;
min-width: 300px;
}
.rp-result-section {
flex: 1;
min-width: 300px;
background: #f8f9fa;
padding: 20px;
border-radius: 6px;
border: 1px solid #eee;
}
.rp-input-group {
margin-bottom: 15px;
}
.rp-input-group label {
display: block;
font-size: 14px;
font-weight: 600;
color: #444;
margin-bottom: 5px;
}
.rp-input-group input, .rp-input-group select {
width: 100%;
padding: 10px;
border: 1px solid #ddd;
border-radius: 4px;
font-size: 15px;
box-sizing: border-box;
}
.rp-input-group input:focus {
border-color: #3498db;
outline: none;
}
.rp-btn-calc {
width: 100%;
background: #27ae60;
color: white;
border: none;
padding: 12px;
font-size: 16px;
font-weight: bold;
border-radius: 4px;
cursor: pointer;
transition: background 0.3s;
margin-top: 10px;
}
.rp-btn-calc:hover {
background: #219150;
}
.rp-result-row {
display: flex;
justify-content: space-between;
padding: 12px 0;
border-bottom: 1px solid #e9ecef;
}
.rp-result-row:last-child {
border-bottom: none;
}
.rp-result-label {
font-size: 14px;
color: #666;
}
.rp-result-value {
font-weight: 700;
font-size: 16px;
color: #2c3e50;
}
.rp-highlight {
color: #27ae60;
font-size: 20px;
}
.rp-highlight-neg {
color: #e74c3c;
font-size: 20px;
}
.rp-content-article {
padding: 40px;
background: #fff;
border-top: 5px solid #2c3e50;
color: #333;
line-height: 1.6;
}
.rp-content-article h2 {
color: #2c3e50;
margin-top: 30px;
font-size: 22px;
}
.rp-content-article h3 {
color: #34495e;
font-size: 18px;
margin-top: 25px;
}
.rp-content-article p {
margin-bottom: 15px;
font-size: 16px;
}
.rp-content-article ul {
margin-bottom: 20px;
padding-left: 20px;
}
.rp-content-article li {
margin-bottom: 8px;
}
@media (max-width: 600px) {
.rp-calc-body {
flex-direction: column;
}
}
Investment Analysis
Monthly Mortgage (P&I):
$0.00
Monthly Operating Expenses:
$0.00
Total Monthly Outflow:
$0.00
Net Monthly Cash Flow:
$0.00
Cash on Cash Return (ROI):
0.00%
Cap Rate:
0.00%
Why Use a Rental Property Cash Flow Calculator?
Successful real estate investing relies on the numbers, not just "gut feelings." This Rental Property Cash Flow Calculator helps investors determine if a property will generate positive income or become a financial burden. By analyzing income against mortgage obligations and operating expenses, you can make data-driven decisions before making an offer.
Understanding Key Real Estate Metrics
When analyzing a rental property, three metrics are critical for assessing performance:
- Net Monthly Cash Flow: This is your profit after all bills are paid. It is calculated as Monthly Rent – (Mortgage + Taxes + Insurance + Maintenance). Positive cash flow is essential for long-term sustainability.
- Cash on Cash Return (CoC): This measures the return on the actual cash you invested (down payment + closing costs), rather than the total loan amount. It tells you how hard your money is working for you. A CoC return of 8-12% is often considered a solid target for residential rentals.
- Cap Rate (Capitalization Rate): This metric evaluates the profitability of a property regardless of financing. It is calculated by dividing the Net Operating Income (NOI) by the property's purchase price. It is useful for comparing properties purchased with cash versus those leveraged with debt.
How to Calculate Rental Cash Flow
To manually estimate your cash flow, follow this simple formula:
Cash Flow = Gross Rental Income – Total Expenses
Where "Total Expenses" includes:
- P&I: Principal and Interest payments on your loan.
- Operating Expenses: Property taxes, hazard insurance, HOA fees, and property management fees.
- Reserves: Money set aside for vacancy (typically 5%) and maintenance/repairs (typically 5-10%).
Use the calculator above to instantly compute these figures. If the result is red (negative), the property costs more to hold than it generates in rent. If it is green (positive), the property is putting money in your pocket every month.
Tips for Improving Cash Flow
If your analysis shows low or negative cash flow, consider negotiating a lower purchase price, increasing the down payment to lower the monthly mortgage, or looking for ways to add value to the property to justify higher rent (e.g., renovations or adding amenities).
function calculateRentalCashFlow() {
// 1. Get Input Values
var price = parseFloat(document.getElementById("rpPurchasePrice").value);
var downPct = parseFloat(document.getElementById("rpDownPayment").value);
var rate = parseFloat(document.getElementById("rpInterestRate").value);
var termYears = parseFloat(document.getElementById("rpLoanTerm").value);
var rent = parseFloat(document.getElementById("rpMonthlyRent").value);
var annualExpenses = parseFloat(document.getElementById("rpExpenses").value);
// Validate Inputs
if (isNaN(price) || isNaN(downPct) || isNaN(rate) || isNaN(termYears) || isNaN(rent) || isNaN(annualExpenses)) {
alert("Please enter valid numbers in all fields.");
return;
}
// 2. Perform Calculations
// Loan Variables
var downPaymentAmount = price * (downPct / 100);
var loanAmount = price – downPaymentAmount;
var monthlyRate = (rate / 100) / 12;
var totalPayments = termYears * 12;
// Monthly Mortgage Payment (Principal + Interest)
// Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
var monthlyMortgage = 0;
if (loanAmount > 0 && rate > 0) {
monthlyMortgage = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, totalPayments)) / (Math.pow(1 + monthlyRate, totalPayments) – 1);
} else if (loanAmount > 0 && rate === 0) {
monthlyMortgage = loanAmount / totalPayments;
}
// Monthly Operating Expenses (Tax, Ins, Maintenance allocated monthly)
var monthlyOpExpenses = annualExpenses / 12;
// Total Monthly Cost
var totalMonthlyCost = monthlyMortgage + monthlyOpExpenses;
// Net Monthly Cash Flow
var cashFlow = rent – totalMonthlyCost;
// Net Operating Income (NOI) -> Rent – Operating Expenses (excluding mortgage)
// Annual NOI
var annualNOI = (rent * 12) – annualExpenses;
// Cap Rate -> (Annual NOI / Purchase Price) * 100
var capRate = (annualNOI / price) * 100;
// Cash on Cash Return -> (Annual Cash Flow / Total Cash Invested) * 100
// Assuming Cash Invested is just Down Payment for this simple tool (ignoring closing costs to keep inputs simple)
var annualCashFlow = cashFlow * 12;
var investedCash = downPaymentAmount;
// Prevent divide by zero if 0 down payment
var cocReturn = 0;
if (investedCash > 0) {
cocReturn = (annualCashFlow / investedCash) * 100;
} else if (investedCash === 0 && annualCashFlow > 0) {
cocReturn = 999; // Infinite return technically
}
// 3. Display Results
document.getElementById("resMortgage").innerText = "$" + monthlyMortgage.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("resExpenses").innerText = "$" + monthlyOpExpenses.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("resTotalCost").innerText = "$" + totalMonthlyCost.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
var cfElement = document.getElementById("resCashFlow");
cfElement.innerText = "$" + cashFlow.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
// Styling based on positive/negative flow
if (cashFlow >= 0) {
cfElement.className = "rp-result-value rp-highlight";
} else {
cfElement.className = "rp-result-value rp-highlight-neg";
}
document.getElementById("resCocReturn").innerText = cocReturn.toFixed(2) + "%";
document.getElementById("resCapRate").innerText = capRate.toFixed(2) + "%";
}
// Run calculation on load to populate defaults
window.onload = function() {
calculateRentalCashFlow();
};