.rpc-calculator-container {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
max-width: 800px;
margin: 0 auto;
padding: 20px;
background: #f9f9f9;
border: 1px solid #e0e0e0;
border-radius: 8px;
}
.rpc-header {
text-align: center;
margin-bottom: 30px;
}
.rpc-header h2 {
color: #2c3e50;
margin-bottom: 10px;
}
.rpc-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
}
@media (max-width: 600px) {
.rpc-grid { grid-template-columns: 1fr; }
}
.rpc-section {
background: #fff;
padding: 20px;
border-radius: 6px;
box-shadow: 0 2px 5px rgba(0,0,0,0.05);
}
.rpc-section h3 {
margin-top: 0;
color: #34495e;
font-size: 1.1em;
border-bottom: 2px solid #3498db;
padding-bottom: 10px;
margin-bottom: 15px;
}
.rpc-input-group {
margin-bottom: 15px;
}
.rpc-input-group label {
display: block;
font-size: 0.9em;
color: #555;
margin-bottom: 5px;
font-weight: 600;
}
.rpc-input-group input {
width: 100%;
padding: 10px;
border: 1px solid #ddd;
border-radius: 4px;
font-size: 1em;
box-sizing: border-box;
}
.rpc-input-group input:focus {
border-color: #3498db;
outline: none;
}
.rpc-btn-container {
text-align: center;
margin: 25px 0;
}
.rpc-btn {
background-color: #27ae60;
color: white;
padding: 15px 40px;
border: none;
border-radius: 5px;
font-size: 1.2em;
cursor: pointer;
transition: background 0.3s;
font-weight: bold;
}
.rpc-btn:hover {
background-color: #219150;
}
.rpc-results {
background-color: #fff;
border: 1px solid #dcdcdc;
border-radius: 6px;
padding: 20px;
margin-top: 20px;
display: none;
}
.rpc-result-row {
display: flex;
justify-content: space-between;
padding: 10px 0;
border-bottom: 1px solid #eee;
}
.rpc-result-row:last-child {
border-bottom: none;
}
.rpc-result-label {
color: #555;
font-weight: 600;
}
.rpc-result-value {
font-weight: bold;
color: #2c3e50;
}
.rpc-highlight {
background-color: #e8f8f5;
padding: 15px;
border-radius: 5px;
margin-top: 10px;
border-left: 5px solid #27ae60;
}
.rpc-highlight .rpc-result-value {
color: #27ae60;
font-size: 1.4em;
}
.rpc-article {
margin-top: 50px;
line-height: 1.6;
color: #333;
max-width: 800px;
margin-left: auto;
margin-right: auto;
}
.rpc-article h2 {
color: #2c3e50;
border-bottom: 1px solid #ddd;
padding-bottom: 10px;
}
.rpc-article h3 {
color: #34495e;
margin-top: 25px;
}
.rpc-article ul {
margin-bottom: 20px;
}
.rpc-article p {
margin-bottom: 15px;
}
function calculateCashFlow() {
// 1. Get Purchase & Loan Inputs
var price = parseFloat(document.getElementById('rpc_price').value);
var downPercent = parseFloat(document.getElementById('rpc_down').value);
var interestRate = parseFloat(document.getElementById('rpc_rate').value);
var loanTerm = parseFloat(document.getElementById('rpc_term').value);
var closingCosts = parseFloat(document.getElementById('rpc_closing').value);
// 2. Get Income Inputs
var monthlyRent = parseFloat(document.getElementById('rpc_rent').value);
var otherIncome = parseFloat(document.getElementById('rpc_other_income').value);
// 3. Get Expense Inputs
var vacancyRate = parseFloat(document.getElementById('rpc_vacancy').value);
var managementRate = parseFloat(document.getElementById('rpc_management').value);
var annualTax = parseFloat(document.getElementById('rpc_tax').value);
var annualInsurance = parseFloat(document.getElementById('rpc_insurance').value);
var monthlyRepairs = parseFloat(document.getElementById('rpc_repairs').value);
var monthlyCapEx = parseFloat(document.getElementById('rpc_capex').value);
var hoaFees = parseFloat(document.getElementById('rpc_hoa').value);
// Validation
if (isNaN(price) || isNaN(monthlyRent) || isNaN(interestRate) || isNaN(loanTerm)) {
alert("Please enter valid numbers for Price, Rent, Interest Rate, and Term.");
return;
}
// Handle defaults for empty optional fields
if (isNaN(closingCosts)) closingCosts = 0;
if (isNaN(otherIncome)) otherIncome = 0;
if (isNaN(vacancyRate)) vacancyRate = 0;
if (isNaN(managementRate)) managementRate = 0;
if (isNaN(annualTax)) annualTax = 0;
if (isNaN(annualInsurance)) annualInsurance = 0;
if (isNaN(monthlyRepairs)) monthlyRepairs = 0;
if (isNaN(monthlyCapEx)) monthlyCapEx = 0;
if (isNaN(hoaFees)) hoaFees = 0;
// — CALCULATIONS —
// Mortgage Calculation
var downPaymentAmount = price * (downPercent / 100);
var loanAmount = price – downPaymentAmount;
var monthlyRate = interestRate / 100 / 12;
var numberOfPayments = loanTerm * 12;
var monthlyPI = 0;
if (interestRate > 0) {
monthlyPI = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, numberOfPayments)) / (Math.pow(1 + monthlyRate, numberOfPayments) – 1);
} else {
monthlyPI = loanAmount / numberOfPayments;
}
// Income Calculations
var totalMonthlyIncome = monthlyRent + otherIncome;
var vacancyLoss = totalMonthlyIncome * (vacancyRate / 100);
var effectiveGrossIncome = totalMonthlyIncome – vacancyLoss;
// Expense Calculations
var managementFee = effectiveGrossIncome * (managementRate / 100);
var monthlyTax = annualTax / 12;
var monthlyInsurance = annualInsurance / 12;
var totalOperatingExpenses = managementFee + monthlyTax + monthlyInsurance + monthlyRepairs + monthlyCapEx + hoaFees;
// Net Operating Income (NOI)
var noi = effectiveGrossIncome – totalOperatingExpenses;
// Cash Flow
var totalMonthlyCashFlow = noi – monthlyPI;
var totalAnnualCashFlow = totalMonthlyCashFlow * 12;
// Returns
var initialCashInvested = downPaymentAmount + closingCosts;
var cashOnCash = 0;
if (initialCashInvested > 0) {
cashOnCash = (totalAnnualCashFlow / initialCashInvested) * 100;
}
var capRate = (noi * 12 / price) * 100;
// — DISPLAY RESULTS —
document.getElementById('res_monthly_income').innerText = "$" + totalMonthlyIncome.toFixed(2);
document.getElementById('res_monthly_expenses').innerText = "$" + totalOperatingExpenses.toFixed(2);
document.getElementById('res_monthly_mortgage').innerText = "$" + monthlyPI.toFixed(2);
document.getElementById('res_noi').innerText = "$" + noi.toFixed(2);
document.getElementById('res_cashflow').innerText = "$" + totalMonthlyCashFlow.toFixed(2);
document.getElementById('res_coc').innerText = cashOnCash.toFixed(2) + "%";
document.getElementById('res_cap').innerText = capRate.toFixed(2) + "%";
document.getElementById('rpc_results_area').style.display = "block";
}
Understanding Rental Property Cash Flow
Investing in real estate is one of the most reliable ways to build wealth, but the difference between a successful investment and a financial burden often comes down to one metric: Cash Flow. This calculator helps you analyze rental properties by breaking down income, expenses, and debt service to reveal the true profitability of a deal.
What is Cash Flow?
Cash flow is the net amount of cash moving into or out of your business (in this case, your rental property). It is calculated as:
Cash Flow = Total Income – Total Expenses – Debt Service
Positive cash flow means the property generates more income than it costs to own and operate, putting money in your pocket every month.
Key Metrics Explained
Net Operating Income (NOI)
NOI is a calculation used to analyze the profitability of income-generating real estate investments. It equals all revenue from the property, minus all necessary operating expenses. Note: NOI does not include mortgage payments or taxes.
Cap Rate (Capitalization Rate)
The Cap Rate indicates the rate of return that is expected to be generated on a real estate investment property. It is calculated by dividing the NOI by the property asset value. It helps compare the profitability of different properties regardless of how they are financed.
Cash-on-Cash Return
This is perhaps the most important metric for investors using leverage (mortgages). It measures the annual return the investor made on the property in relation to the amount of mortgage paid during the same year.
Formula: Annual Pre-Tax Cash Flow / Total Cash Invested
For example, if you invest $50,000 (down payment + closing costs) and the property generates $5,000 in positive cash flow per year, your Cash-on-Cash return is 10%.
Estimating Expenses Accurately
The biggest mistake new investors make is underestimating expenses. When using this Rental Property Calculator, ensure you account for:
- Vacancy: Properties will not be occupied 365 days a year. A standard conservative estimate is 5-8%.
- Repairs & Maintenance: Things break. Budgeting 5-10% of rent for routine repairs is wise.
- CapEx (Capital Expenditures): These are big-ticket items like a new roof or HVAC system. Setting aside reserves monthly prevents cash flow shock later.
- Property Management: Even if you self-manage, you should account for your time or the future cost of a manager (typically 8-10% of rent).