.rpc-calculator-container {
max-width: 800px;
margin: 0 auto;
padding: 20px;
background: #f9f9f9;
border: 1px solid #ddd;
border-radius: 8px;
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}
.rpc-header {
text-align: center;
margin-bottom: 25px;
}
.rpc-header h2 {
margin: 0;
color: #333;
font-size: 24px;
}
.rpc-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
}
@media (max-width: 600px) {
.rpc-grid {
grid-template-columns: 1fr;
}
}
.rpc-input-group {
margin-bottom: 15px;
}
.rpc-input-group label {
display: block;
margin-bottom: 5px;
font-weight: 600;
color: #555;
font-size: 14px;
}
.rpc-input-group input {
width: 100%;
padding: 10px;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
.rpc-input-group input:focus {
border-color: #0073aa;
outline: none;
}
.rpc-section-title {
grid-column: 1 / -1;
font-size: 18px;
color: #0073aa;
border-bottom: 2px solid #e1e1e1;
padding-bottom: 10px;
margin-top: 20px;
margin-bottom: 15px;
}
.rpc-button-container {
grid-column: 1 / -1;
text-align: center;
margin-top: 20px;
}
.rpc-btn {
background-color: #0073aa;
color: white;
border: none;
padding: 12px 30px;
font-size: 18px;
border-radius: 5px;
cursor: pointer;
transition: background-color 0.3s;
}
.rpc-btn:hover {
background-color: #005177;
}
.rpc-results {
grid-column: 1 / -1;
background: #fff;
border: 1px solid #e1e1e1;
border-radius: 8px;
padding: 20px;
margin-top: 25px;
display: none;
}
.rpc-result-row {
display: flex;
justify-content: space-between;
padding: 10px 0;
border-bottom: 1px solid #f0f0f0;
}
.rpc-result-row:last-child {
border-bottom: none;
}
.rpc-result-label {
color: #666;
}
.rpc-result-value {
font-weight: bold;
color: #333;
}
.rpc-highlight {
background-color: #f0f8ff;
padding: 10px;
border-radius: 4px;
font-size: 1.1em;
}
.rpc-positive {
color: #28a745;
}
.rpc-negative {
color: #dc3545;
}
function calculateCashFlow() {
// Get Inputs
var price = parseFloat(document.getElementById('rpcPrice').value) || 0;
var down = parseFloat(document.getElementById('rpcDown').value) || 0;
var rate = parseFloat(document.getElementById('rpcRate').value) || 0;
var term = parseFloat(document.getElementById('rpcTerm').value) || 0;
var rent = parseFloat(document.getElementById('rpcRent').value) || 0;
var tax = parseFloat(document.getElementById('rpcTax').value) || 0;
var insurance = parseFloat(document.getElementById('rpcInsurance').value) || 0;
var hoa = parseFloat(document.getElementById('rpcHoa').value) || 0;
var repairPct = parseFloat(document.getElementById('rpcRepairs').value) || 0;
var vacancyPct = parseFloat(document.getElementById('rpcVacancy').value) || 0;
var mgmtPct = parseFloat(document.getElementById('rpcMgmt').value) || 0;
// 1. Calculate Mortgage
var loanAmount = price – down;
var monthlyMortgage = 0;
if (loanAmount > 0 && rate > 0 && term > 0) {
var monthlyRate = (rate / 100) / 12;
var numPayments = term * 12;
monthlyMortgage = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, numPayments)) / (Math.pow(1 + monthlyRate, numPayments) – 1);
}
// 2. Calculate Monthly Operating Expenses
var monthlyTax = tax / 12;
var monthlyIns = insurance / 12;
var monthlyRepairs = rent * (repairPct / 100);
var monthlyVacancy = rent * (vacancyPct / 100);
var monthlyMgmt = rent * (mgmtPct / 100);
var totalOperatingExpenses = monthlyTax + monthlyIns + hoa + monthlyRepairs + monthlyVacancy + monthlyMgmt;
var totalExpenses = totalOperatingExpenses + monthlyMortgage;
// 3. Calculate Metrics
var monthlyNOI = rent – totalOperatingExpenses;
var monthlyCashFlow = rent – totalExpenses;
var annualCashFlow = monthlyCashFlow * 12;
var annualNOI = monthlyNOI * 12;
// Cash on Cash Return = Annual Cash Flow / Invested Cash
// Invested Cash usually includes closing costs and rehab, but we use Down Payment here for simplicity as per inputs
var cashInvested = down;
var cocReturn = 0;
if (cashInvested > 0) {
cocReturn = (annualCashFlow / cashInvested) * 100;
}
// Cap Rate = Annual NOI / Purchase Price
var capRate = 0;
if (price > 0) {
capRate = (annualNOI / price) * 100;
}
// Display Results
document.getElementById('resMortgage').innerText = formatCurrency(monthlyMortgage);
document.getElementById('resTotalExp').innerText = formatCurrency(totalExpenses);
document.getElementById('resNOI').innerText = formatCurrency(monthlyNOI);
var cfElement = document.getElementById('resCashFlow');
cfElement.innerText = formatCurrency(monthlyCashFlow);
if(monthlyCashFlow >= 0) {
cfElement.className = "rpc-result-value rpc-positive";
} else {
cfElement.className = "rpc-result-value rpc-negative";
}
document.getElementById('resCoc').innerText = cocReturn.toFixed(2) + '%';
document.getElementById('resCap').innerText = capRate.toFixed(2) + '%';
document.getElementById('rpcResults').style.display = 'block';
}
function formatCurrency(num) {
return '$' + num.toFixed(2).replace(/\d(?=(\d{3})+\.)/g, '$&,');
}
Understanding Rental Property Cash Flow
Investing in real estate is a powerful way to build wealth, but the difference between a successful investment and a financial burden often comes down to one metric: Cash Flow. Our Rental Property Cash Flow Calculator helps you break down the numbers to see if a property will generate monthly income or cost you money out of pocket.
How is Cash Flow Calculated?
Cash flow is essentially the money left over after all expenses are paid. The basic formula used in this calculator is:
Cash Flow = Gross Rental Income – Total Expenses
Where "Total Expenses" includes:
- Mortgage Payment (P&I): Principal and Interest on your loan.
- Operating Expenses: Property taxes, insurance, HOA fees.
- Reserves: Money set aside for vacancy, repairs, and property management.
Key Metrics Defined
Beyond simple cash flow, this calculator provides two critical metrics for investors:
1. Cash on Cash Return (CoC ROI)
This measures the return on the actual cash you invested (down payment), not the total price of the home. It is calculated as:
(Annual Cash Flow / Total Cash Invested) × 100
For example, if you put $50,000 down and the property generates $3,000 in positive cash flow per year, your Cash on Cash return is 6%.
2. Cap Rate (Capitalization Rate)
Cap Rate measures the natural rate of return of the property assuming you paid all cash (no mortgage). It helps you compare properties regardless of financing. It is calculated as:
(Net Operating Income / Purchase Price) × 100
Example Scenario
Let's say you are looking at a single-family home for $250,000.
- You put 20% down ($50,000).
- You secure a loan at 6.5% interest.
- The property rents for $2,200/month.
After accounting for taxes ($3,000/yr), insurance ($1,200/yr), and setting aside 10% for repairs and vacancy, your mortgage payment might be around $1,264. Adding in other expenses, your total monthly outflow could be roughly $1,834.
Result: You would have a positive monthly cash flow of approx $366. This is the "passive income" investors strive for.
Why Use a Cash Flow Calculator?
Never rely on "napkin math." Small expenses like vacancy rates (weeks where the property sits empty) and maintenance reserves (saving for a new roof or water heater) can quickly turn a profitable looking property into a negative cash flow asset. Using a detailed tool ensures you account for the hidden costs of ownership.