.calc-wrapper {
max-width: 800px;
margin: 0 auto;
font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
color: #333;
line-height: 1.6;
}
.calculator-box {
background: #f9f9f9;
border: 1px solid #e0e0e0;
border-radius: 8px;
padding: 30px;
box-shadow: 0 4px 6px rgba(0,0,0,0.05);
margin-bottom: 40px;
}
.calc-title {
text-align: center;
color: #2c3e50;
margin-bottom: 25px;
font-size: 24px;
font-weight: 700;
}
.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: 5px;
font-weight: 600;
font-size: 14px;
}
.input-group input {
width: 100%;
padding: 10px;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
.section-header {
grid-column: 1 / -1;
font-size: 18px;
border-bottom: 2px solid #ddd;
padding-bottom: 5px;
margin-top: 10px;
margin-bottom: 10px;
color: #555;
}
.calc-btn {
grid-column: 1 / -1;
background-color: #27ae60;
color: white;
border: none;
padding: 15px;
font-size: 18px;
border-radius: 5px;
cursor: pointer;
width: 100%;
margin-top: 10px;
transition: background 0.3s;
}
.calc-btn:hover {
background-color: #219150;
}
#results-area {
display: none;
grid-column: 1 / -1;
margin-top: 30px;
background: #fff;
padding: 20px;
border-radius: 5px;
border: 1px solid #ddd;
}
.result-row {
display: flex;
justify-content: space-between;
padding: 10px 0;
border-bottom: 1px solid #eee;
}
.result-row.highlight {
font-weight: bold;
font-size: 1.1em;
color: #2c3e50;
border-bottom: 2px solid #27ae60;
}
.metric-cards {
display: grid;
grid-template-columns: repeat(3, 1fr);
gap: 10px;
margin-top: 20px;
}
.metric-card {
background: #f0f4c3;
padding: 15px;
text-align: center;
border-radius: 5px;
}
.metric-card.positive { background: #e8f5e9; color: #2e7d32; }
.metric-card.negative { background: #ffebee; color: #c62828; }
.metric-label { font-size: 12px; text-transform: uppercase; color: #666; }
.metric-value { font-size: 20px; font-weight: bold; margin-top: 5px; }
/* Article Styles */
.content-article h2 { color: #2c3e50; margin-top: 30px; }
.content-article h3 { color: #34495e; }
.content-article p { margin-bottom: 15px; }
.content-article ul { margin-bottom: 15px; padding-left: 20px; }
.content-article li { margin-bottom: 8px; }
function calculateROI() {
// Inputs: Purchase & Loan
var price = parseFloat(document.getElementById('purchasePrice').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;
// Inputs: Income
var rent = parseFloat(document.getElementById('monthlyRent').value) || 0;
var vacancyPct = parseFloat(document.getElementById('vacancyRate').value) || 0;
// Inputs: Expenses
var annualTax = parseFloat(document.getElementById('propertyTax').value) || 0;
var annualIns = parseFloat(document.getElementById('insurance').value) || 0;
var monthlyHOA = parseFloat(document.getElementById('hoaFees').value) || 0;
var maintPct = parseFloat(document.getElementById('maintenance').value) || 0;
// Calculations
var loanAmount = price – down;
// Mortgage (P&I)
var monthlyRate = (rate / 100) / 12;
var totalPayments = years * 12;
var mortgagePayment = 0;
if (rate > 0) {
mortgagePayment = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, totalPayments)) / (Math.pow(1 + monthlyRate, totalPayments) – 1);
} else {
mortgagePayment = loanAmount / totalPayments;
}
// Vacancy Loss
var vacancyLoss = rent * (vacancyPct / 100);
var effectiveRent = rent – vacancyLoss;
// Operating Expenses
var monthlyTax = annualTax / 12;
var monthlyIns = annualIns / 12;
var monthlyMaint = rent * (maintPct / 100);
var totalOpEx = monthlyTax + monthlyIns + monthlyHOA + monthlyMaint;
// Cash Flow
var netOperatingIncome = effectiveRent – totalOpEx; // NOI
var monthlyCashFlow = netOperatingIncome – mortgagePayment;
var annualCashFlow = monthlyCashFlow * 12;
// ROI Metrics
var cocReturn = 0;
if (down > 0) {
cocReturn = (annualCashFlow / down) * 100;
}
var capRate = 0;
if (price > 0) {
var annualNOI = netOperatingIncome * 12;
capRate = (annualNOI / price) * 100;
}
// Display Results
document.getElementById('results-area').style.display = 'block';
// Helper for formatting currency
function formatMoney(num) {
return '$' + num.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
}
document.getElementById('res-gross-rent').innerText = formatMoney(rent);
document.getElementById('res-vacancy').innerText = formatMoney(vacancyLoss);
document.getElementById('res-mortgage').innerText = formatMoney(mortgagePayment);
document.getElementById('res-opex').innerText = formatMoney(totalOpEx);
var netEl = document.getElementById('res-net-final');
netEl.innerText = formatMoney(monthlyCashFlow);
netEl.style.color = monthlyCashFlow >= 0 ? '#27ae60' : '#c0392b';
// Cards
var cfCard = document.getElementById('res-monthly-cashflow');
cfCard.innerText = formatMoney(monthlyCashFlow);
document.getElementById('card-cashflow').className = 'metric-card ' + (monthlyCashFlow >= 0 ? 'positive' : 'negative');
var cocEl = document.getElementById('res-coc');
cocEl.innerText = cocReturn.toFixed(2) + '%';
document.getElementById('card-coc').className = 'metric-card ' + (cocReturn >= 0 ? 'positive' : 'negative');
var capEl = document.getElementById('res-cap');
capEl.innerText = capRate.toFixed(2) + '%';
}
Rental Property Cash Flow Analysis
Investing in real estate is one of the most reliable ways to build wealth, but simply buying a property doesn't guarantee profit. To be a successful investor, you must understand the numbers behind the deal. This Rental Property Cash Flow Calculator helps you analyze potential investments by breaking down income, operating expenses, and debt service to reveal the true profitability of a rental unit.
How to Calculate Rental Property Cash Flow
Cash flow is the net amount of money moving into or out of a business or investment. In real estate, it is calculated as:
Cash Flow = Gross Rental Income – (Vacancy + Operating Expenses + Debt Service)
A positive cash flow indicates that the property is generating profit every month after all bills are paid, while a negative cash flow means the property is costing you money to hold.
Key Inputs Explained
- Gross Monthly Rent: The total amount you charge tenants per month.
- Vacancy Rate: Properties are rarely occupied 365 days a year. A standard vacancy rate to factor in is 5% to 10% (equivalent to 2-4 weeks vacant per year).
- Maintenance & Repairs: Even new homes break. Smart investors set aside 5% to 15% of the monthly rent for future repairs (HVAC, roof, painting).
- CapEx (Capital Expenditures): Major replacements like roofs or boilers. Our calculator groups this with maintenance, but ensure your percentage is high enough to cover these long-term costs.
Understanding the ROI Metrics
This calculator provides three critical metrics to help you make a decision:
1. Monthly Cash Flow
This is your "take-home" pay from the property. Most investors look for at least $100-$200 per door in pure positive cash flow for a property to be considered a safe investment.
2. Cash on Cash Return (CoC)
This metric measures the annual return on the actual cash you invested (Down Payment + Closing Costs). It compares your profit to your out-of-pocket cash rather than the total loan amount.
Formula: (Annual Pre-Tax Cash Flow / Total Cash Invested) x 100
A good CoC return depends on the market, but many investors target 8% to 12%.
3. Cap Rate (Capitalization Rate)
The Cap Rate measures the property's natural rate of return assuming it was bought with cash (no loan). It is useful for comparing the profitability of different properties regardless of how they are financed.
Formula: (Net Operating Income / Purchase Price) x 100
Why Operating Expenses Matter
Novice investors often underestimate expenses. They subtract the mortgage from the rent and assume the rest is profit. This is a dangerous mistake. You must account for Property Taxes, Insurance, HOA fees, Landscaping, and Property Management fees (even if you self-manage, your time has value). Using a detailed calculator like the one above ensures you don't buy a liability thinking it's an asset.