.calculator-wrapper {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
max-width: 800px;
margin: 0 auto;
background: #fff;
padding: 20px;
border: 1px solid #e0e0e0;
border-radius: 8px;
box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}
.calc-header {
text-align: center;
margin-bottom: 30px;
background-color: #f8f9fa;
padding: 20px;
border-radius: 8px;
}
.calc-header h2 {
margin: 0;
color: #2c3e50;
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;
}
.section-title {
grid-column: 1 / -1;
font-size: 18px;
font-weight: bold;
color: #2c3e50;
margin-top: 10px;
margin-bottom: 10px;
border-bottom: 2px solid #3498db;
padding-bottom: 5px;
}
.btn-container {
grid-column: 1 / -1;
text-align: center;
margin-top: 20px;
}
button.calc-btn {
background-color: #27ae60;
color: white;
border: none;
padding: 15px 40px;
font-size: 18px;
font-weight: bold;
border-radius: 5px;
cursor: pointer;
transition: background 0.3s;
}
button.calc-btn:hover {
background-color: #219150;
}
#results-area {
display: none;
grid-column: 1 / -1;
margin-top: 30px;
background-color: #f0f8ff;
padding: 20px;
border-radius: 8px;
border: 1px solid #bcdff1;
}
.result-row {
display: flex;
justify-content: space-between;
padding: 10px 0;
border-bottom: 1px solid #dceefc;
}
.result-row:last-child {
border-bottom: none;
}
.result-label {
font-weight: 600;
color: #444;
}
.result-value {
font-weight: bold;
color: #2c3e50;
font-size: 18px;
}
.positive {
color: #27ae60;
}
.negative {
color: #c0392b;
}
.content-section {
margin-top: 50px;
line-height: 1.6;
color: #333;
}
.content-section h2 {
font-size: 22px;
color: #2c3e50;
margin-top: 30px;
}
.content-section p {
margin-bottom: 15px;
}
.content-section ul {
margin-bottom: 20px;
}
.content-section li {
margin-bottom: 8px;
}
function calculateRental() {
// Get inputs
var purchasePrice = parseFloat(document.getElementById("purchasePrice").value);
var downPayment = parseFloat(document.getElementById("downPayment").value);
var closingCosts = parseFloat(document.getElementById("closingCosts").value);
var interestRate = parseFloat(document.getElementById("interestRate").value);
var loanTerm = parseFloat(document.getElementById("loanTerm").value);
var monthlyRent = parseFloat(document.getElementById("monthlyRent").value);
var propertyTax = parseFloat(document.getElementById("propertyTax").value);
var insurance = parseFloat(document.getElementById("insurance").value);
var hoa = parseFloat(document.getElementById("hoa").value);
var maintenance = parseFloat(document.getElementById("maintenance").value);
// Validation
if (isNaN(purchasePrice) || isNaN(downPayment) || isNaN(interestRate) || isNaN(loanTerm) || isNaN(monthlyRent)) {
alert("Please fill in all required fields (Price, Down Payment, Rate, Term, Rent) to calculate.");
return;
}
// Default optional fields to 0 if empty
if (isNaN(closingCosts)) closingCosts = 0;
if (isNaN(propertyTax)) propertyTax = 0;
if (isNaN(insurance)) insurance = 0;
if (isNaN(hoa)) hoa = 0;
if (isNaN(maintenance)) maintenance = 0;
// Mortgage Calculation
var loanAmount = purchasePrice – downPayment;
var monthlyRate = (interestRate / 100) / 12;
var numberOfPayments = loanTerm * 12;
var monthlyMortgage = 0;
if (interestRate === 0) {
monthlyMortgage = loanAmount / numberOfPayments;
} else {
monthlyMortgage = (loanAmount * monthlyRate * Math.pow(1 + monthlyRate, numberOfPayments)) / (Math.pow(1 + monthlyRate, numberOfPayments) – 1);
}
// Expense Calculation
var monthlyTax = propertyTax / 12;
var monthlyInsurance = insurance / 12;
var totalMonthlyExpenses = monthlyMortgage + monthlyTax + monthlyInsurance + hoa + maintenance;
// Cash Flow Calculation
var monthlyCashFlow = monthlyRent – totalMonthlyExpenses;
var annualCashFlow = monthlyCashFlow * 12;
// ROI Calculation (Cash on Cash)
var totalCashInvested = downPayment + closingCosts;
var roi = 0;
if (totalCashInvested > 0) {
roi = (annualCashFlow / totalCashInvested) * 100;
}
// Display Results
document.getElementById("results-area").style.display = "block";
// Format Currency Function
var fmt = new Intl.NumberFormat('en-US', { style: 'currency', currency: 'USD' });
document.getElementById("resMortgage").innerText = fmt.format(monthlyMortgage);
document.getElementById("resExpenses").innerText = fmt.format(totalMonthlyExpenses);
var cashFlowEl = document.getElementById("resCashFlow");
cashFlowEl.innerText = fmt.format(monthlyCashFlow);
cashFlowEl.className = "result-value " + (monthlyCashFlow >= 0 ? "positive" : "negative");
var annualEl = document.getElementById("resAnnualCashFlow");
annualEl.innerText = fmt.format(annualCashFlow);
annualEl.className = "result-value " + (annualCashFlow >= 0 ? "positive" : "negative");
var roiEl = document.getElementById("resROI");
roiEl.innerText = roi.toFixed(2) + "%";
roiEl.className = "result-value " + (roi >= 0 ? "positive" : "negative");
}
How to Analyze Rental Property Deals
Investing in real estate is one of the most reliable ways to build wealth, but simply buying a property and renting it out doesn't guarantee a profit. Successful real estate investors rely on the numbers, not their gut feelings. This Rental Property Cash Flow Calculator is designed to help you determine the viability of a potential investment by analyzing the two most critical metrics: Cash Flow and Cash on Cash Return.
What is Rental Property Cash Flow?
Cash flow is the profit you bring in each month after all operating expenses and mortgage payments have been paid. It is calculated using the formula:
Cash Flow = Total Income – Total Expenses
Positive cash flow means the property pays for itself and puts money in your pocket. Negative cash flow means you are losing money every month to hold the property. While some investors bank on appreciation (the property value going up), veteran investors prioritize cash flow to ensure the asset is sustainable.
Understanding Cash on Cash Return (ROI)
While cash flow tells you how much money you make, Cash on Cash Return tells you how hard your money is working. It compares your annual pre-tax cash flow to the total amount of cash you actually invested (Down Payment + Closing Costs + Rehab Costs).
For example, if you invest $50,000 cash to buy a property and it generates $5,000 in net positive cash flow per year, your Cash on Cash return is 10%. This metric allows you to compare real estate returns against other investment vehicles like the stock market or bonds.
Key Inputs for Accurate Calculation
- Vacancy Rate: Always account for vacancy. Even in hot markets, you will have turnover. A standard conservative estimate is 5-8% of the gross rent (included in our Maintenance/CapEx field for simplicity or deducted from rent manually).
- CapEx (Capital Expenditures): Roofs, HVAC systems, and water heaters eventually break. You should set aside a portion of rent every month (budgeted here under Maintenance) to pay for these big-ticket items when they arise.
- Property Management: Even if you plan to manage it yourself, it is wise to calculate the numbers assuming you pay a property manager (typically 8-10% of rent). If the deal only works when you work for free, it's not a passive investment.
What is a Good ROI for Rental Property?
Target returns vary by investor strategy and location. Generally, a Cash on Cash return of 8% to 12% is considered solid for a standard long-term rental. In high-appreciation markets, investors might accept lower cash flow (4-6%), while in stable cash-flow markets, investors often look for 12% or higher.