.calculator-widget {
font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
max-width: 800px;
margin: 0 auto;
background: #ffffff;
border: 1px solid #e0e0e0;
border-radius: 8px;
box-shadow: 0 4px 12px rgba(0,0,0,0.05);
padding: 0;
}
.calc-header {
background: #2c3e50;
color: white;
padding: 20px;
border-radius: 8px 8px 0 0;
text-align: center;
}
.calc-header h2 {
margin: 0;
font-size: 24px;
}
.calc-body {
padding: 25px;
display: flex;
flex-wrap: wrap;
gap: 20px;
}
.input-group {
flex: 1 1 300px;
display: flex;
flex-direction: column;
margin-bottom: 15px;
}
.input-group label {
font-weight: 600;
color: #333;
margin-bottom: 8px;
font-size: 14px;
}
.input-wrapper {
position: relative;
display: flex;
align-items: center;
}
.input-prefix, .input-suffix {
background: #f4f6f8;
color: #555;
padding: 10px 12px;
border: 1px solid #ccc;
font-weight: bold;
font-size: 14px;
}
.input-prefix {
border-right: none;
border-radius: 4px 0 0 4px;
}
.input-suffix {
border-left: none;
border-radius: 0 4px 4px 0;
}
.calc-input {
flex: 1;
padding: 10px;
border: 1px solid #ccc;
font-size: 16px;
outline: none;
transition: border 0.3s;
}
.calc-input:focus {
border-color: #2c3e50;
}
.calc-input.has-prefix {
border-radius: 0 4px 4px 0;
}
.calc-input.has-suffix {
border-radius: 4px 0 0 4px;
}
.calc-input.has-both {
border-radius: 0;
}
.calc-btn-container {
width: 100%;
text-align: center;
margin-top: 10px;
}
.calc-btn {
background: #27ae60;
color: white;
border: none;
padding: 15px 40px;
font-size: 18px;
font-weight: bold;
border-radius: 5px;
cursor: pointer;
transition: background 0.2s;
}
.calc-btn:hover {
background: #219150;
}
.results-section {
background: #f8f9fa;
border-top: 1px solid #e0e0e0;
padding: 25px;
border-radius: 0 0 8px 8px;
display: none;
}
.results-grid {
display: grid;
grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
gap: 20px;
}
.result-card {
background: white;
padding: 15px;
border-radius: 6px;
box-shadow: 0 2px 5px rgba(0,0,0,0.05);
text-align: center;
border-left: 4px solid #2c3e50;
}
.result-card.highlight {
border-left: 4px solid #27ae60;
background: #eafff2;
}
.result-label {
font-size: 13px;
text-transform: uppercase;
color: #666;
letter-spacing: 0.5px;
margin-bottom: 5px;
}
.result-value {
font-size: 24px;
font-weight: 800;
color: #2c3e50;
}
.positive-flow { color: #27ae60; }
.negative-flow { color: #c0392b; }
/* Article Styles */
.seo-content {
max-width: 800px;
margin: 40px auto;
font-family: 'Segoe UI', Roboto, sans-serif;
line-height: 1.6;
color: #333;
}
.seo-content h2 {
color: #2c3e50;
margin-top: 30px;
border-bottom: 2px solid #27ae60;
padding-bottom: 10px;
display: inline-block;
}
.seo-content h3 {
color: #444;
margin-top: 25px;
}
.seo-content ul {
background: #f9f9f9;
padding: 20px 40px;
border-radius: 5px;
border-left: 4px solid #2c3e50;
}
.seo-content li {
margin-bottom: 10px;
}
.seo-content p {
margin-bottom: 15px;
}
function calculateRentalROI() {
// 1. Get Inputs
var price = parseFloat(document.getElementById('propPrice').value) || 0;
var down = parseFloat(document.getElementById('downPayment').value) || 0;
var rate = parseFloat(document.getElementById('interestRate').value) || 0;
var years = parseFloat(document.getElementById('loanTerm').value) || 0;
var rent = parseFloat(document.getElementById('monthlyRent').value) || 0;
var tax = parseFloat(document.getElementById('propTax').value) || 0;
var ins = parseFloat(document.getElementById('insurance').value) || 0;
var maintPercent = parseFloat(document.getElementById('maintenance').value) || 0;
// 2. Loan Calculations
var principal = price – down;
var monthlyRate = rate / 100 / 12;
var numPayments = years * 12;
var mortgagePayment = 0;
if (monthlyRate > 0 && numPayments > 0) {
mortgagePayment = principal * (monthlyRate * Math.pow(1 + monthlyRate, numPayments)) / (Math.pow(1 + monthlyRate, numPayments) – 1);
} else {
mortgagePayment = 0;
}
// 3. Operating Expenses
var monthlyTax = tax / 12;
var monthlyIns = ins / 12;
var monthlyMaint = rent * (maintPercent / 100);
var totalOperatingExpenses = monthlyTax + monthlyIns + monthlyMaint; // Excludes Mortgage
var totalMonthlyOutflow = totalOperatingExpenses + mortgagePayment;
// 4. Key Metrics
var monthlyCashFlow = rent – totalMonthlyOutflow;
var annualCashFlow = monthlyCashFlow * 12;
var annualNOI = (rent * 12) – (totalOperatingExpenses * 12); // Net Operating Income (Pre-debt service)
var cocRoi = 0;
if (down > 0) {
cocRoi = (annualCashFlow / down) * 100;
}
var capRate = 0;
if (price > 0) {
capRate = (annualNOI / price) * 100;
}
// 5. Display Results
document.getElementById('resultSection').style.display = 'block';
var flowEl = document.getElementById('resCashFlow');
flowEl.innerText = '$' + monthlyCashFlow.toFixed(2);
flowEl.className = 'result-value ' + (monthlyCashFlow >= 0 ? 'positive-flow' : 'negative-flow');
document.getElementById('resCoc').innerText = cocRoi.toFixed(2) + '%';
document.getElementById('resCapRate').innerText = capRate.toFixed(2) + '%';
document.getElementById('resExpenses').innerText = '$' + totalMonthlyOutflow.toFixed(2);
}
Understanding Rental Property Investment Metrics
Investing in real estate is a numbers game. Whether you are a seasoned investor or buying your first rental property, accurately calculating your potential return on investment (ROI) is crucial. This Rental Property Cash Flow Calculator helps you analyze a deal by breaking down the three most important metrics: Monthly Cash Flow, Cash-on-Cash Return, and Cap Rate.
1. Monthly Cash Flow
Cash flow is the profit you bring in each month after all expenses are paid. It is calculated as:
- Gross Income: Your total monthly rent.
- Minus Operating Expenses: Taxes, insurance, HOA fees, maintenance reserves, and vacancy allowances.
- Minus Debt Service: Your monthly mortgage principal and interest payment.
A positive cash flow means the property pays for itself and generates income. A negative cash flow means you must pay out of pocket every month to keep the property.
2. Cash-on-Cash Return (CoC ROI)
This metric tells you how hard your actual invested cash is working. Unlike simple ROI, which might look at the total property value, Cash-on-Cash ROI focuses on the money you actually put down (Down Payment + Closing Costs).
Formula: Annual Cash Flow / Total Cash Invested
For example, if you put $50,000 down and the property generates $5,000 in annual profit, your CoC ROI is 10%. This allows you to compare real estate returns directly against other investments like stocks or bonds.
3. Cap Rate (Capitalization Rate)
Cap Rate measures the natural profitability of the property itself, independent of how you finance it. It is calculated using the Net Operating Income (NOI) divided by the Purchase Price.
Investors use Cap Rate to compare similar properties in the same market. A higher Cap Rate generally implies a better return but may come with higher risk or a less desirable location. Note that Cap Rate does not account for your mortgage payments.
Why Maintenance and Vacancy Reserves Matter
Many new investors make the mistake of calculating returns assuming the property will be occupied 100% of the time and nothing will break. This is unrealistic.
Our calculator includes a field for "Maint. & Vacancy Reserve". A prudent investor typically sets aside 10% to 15% of the monthly rent to cover future repairs (like a new roof or HVAC) and months where the unit sits empty between tenants. Ignoring these costs can turn a seemingly profitable deal into a financial burden.