Rental Property Cash Flow Calculator
.rpc-calculator-container {
max-width: 800px;
margin: 0 auto;
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
color: #333;
background: #fff;
border: 1px solid #e0e0e0;
border-radius: 8px;
box-shadow: 0 4px 6px rgba(0,0,0,0.05);
overflow: hidden;
}
.rpc-header {
background-color: #2c3e50;
color: #fff;
padding: 20px;
text-align: center;
}
.rpc-header h2 {
margin: 0;
font-size: 24px;
}
.rpc-body {
padding: 30px;
display: flex;
flex-wrap: wrap;
gap: 30px;
}
.rpc-input-section {
flex: 1;
min-width: 300px;
}
.rpc-result-section {
flex: 1;
min-width: 300px;
background-color: #f8f9fa;
padding: 20px;
border-radius: 6px;
border: 1px solid #dee2e6;
display: flex;
flex-direction: column;
justify-content: center;
}
.rpc-form-group {
margin-bottom: 15px;
}
.rpc-form-group label {
display: block;
margin-bottom: 5px;
font-weight: 600;
font-size: 14px;
}
.rpc-form-group input {
width: 100%;
padding: 10px;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
.rpc-form-group .rpc-input-wrapper {
position: relative;
}
.rpc-btn {
width: 100%;
padding: 12px;
background-color: #27ae60;
color: white;
border: none;
border-radius: 4px;
font-size: 16px;
font-weight: bold;
cursor: pointer;
transition: background-color 0.2s;
margin-top: 10px;
}
.rpc-btn:hover {
background-color: #219150;
}
.rpc-result-row {
display: flex;
justify-content: space-between;
align-items: center;
padding: 10px 0;
border-bottom: 1px solid #e9ecef;
}
.rpc-result-row:last-child {
border-bottom: none;
}
.rpc-result-label {
font-size: 14px;
color: #666;
}
.rpc-result-value {
font-size: 18px;
font-weight: bold;
color: #2c3e50;
}
.rpc-main-result {
text-align: center;
margin-top: 20px;
padding-top: 20px;
border-top: 2px solid #dee2e6;
}
.rpc-main-result .rpc-label {
font-size: 16px;
color: #666;
margin-bottom: 5px;
display: block;
}
.rpc-main-result .rpc-value {
font-size: 32px;
font-weight: 800;
color: #27ae60;
}
.rpc-main-result .rpc-value.negative {
color: #c0392b;
}
.rpc-article {
max-width: 800px;
margin: 40px auto;
line-height: 1.6;
color: #444;
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}
.rpc-article h2 {
color: #2c3e50;
margin-top: 30px;
}
.rpc-article h3 {
color: #34495e;
margin-top: 20px;
}
.rpc-article ul {
margin-bottom: 20px;
}
.rpc-article li {
margin-bottom: 10px;
}
Monthly Mortgage Payment:
$0.00
Total Monthly Expenses:
$0.00
Initial Cash Investment:
$0.00
Estimated Monthly Cash Flow
$0.00
Cash on Cash ROI
0.00%
function calculateRentalCashFlow() {
// Get Input Values
var price = parseFloat(document.getElementById('rpc_price').value);
var downPercent = parseFloat(document.getElementById('rpc_down_percent').value);
var interestRate = parseFloat(document.getElementById('rpc_interest').value);
var years = parseFloat(document.getElementById('rpc_term').value);
var monthlyRent = parseFloat(document.getElementById('rpc_rent').value);
var otherExpenses = parseFloat(document.getElementById('rpc_expenses').value);
// Validation
if (isNaN(price) || isNaN(downPercent) || isNaN(interestRate) || isNaN(years) || isNaN(monthlyRent) || isNaN(otherExpenses)) {
alert("Please enter valid numbers in all fields.");
return;
}
// Calculations
var downPaymentAmount = price * (downPercent / 100);
var loanAmount = price – downPaymentAmount;
// Mortgage Calculation
var monthlyRate = (interestRate / 100) / 12;
var numberOfPayments = years * 12;
var mortgagePayment = 0;
if (interestRate === 0) {
mortgagePayment = loanAmount / numberOfPayments;
} else {
mortgagePayment = (loanAmount * monthlyRate * Math.pow(1 + monthlyRate, numberOfPayments)) / (Math.pow(1 + monthlyRate, numberOfPayments) – 1);
}
var totalMonthlyExpenses = mortgagePayment + otherExpenses;
var monthlyCashFlow = monthlyRent – totalMonthlyExpenses;
var annualCashFlow = monthlyCashFlow * 12;
var cashOnCashRoi = 0;
if (downPaymentAmount > 0) {
cashOnCashRoi = (annualCashFlow / downPaymentAmount) * 100;
}
// Display Results
document.getElementById('rpc_res_mortgage').innerText = formatCurrency(mortgagePayment);
document.getElementById('rpc_res_total_exp').innerText = formatCurrency(totalMonthlyExpenses);
document.getElementById('rpc_res_investment').innerText = formatCurrency(downPaymentAmount);
var cashFlowEl = document.getElementById('rpc_res_cashflow');
cashFlowEl.innerText = formatCurrency(monthlyCashFlow);
if (monthlyCashFlow < 0) {
cashFlowEl.classList.add('negative');
} else {
cashFlowEl.classList.remove('negative');
}
document.getElementById('rpc_res_roi').innerText = cashOnCashRoi.toFixed(2) + "%";
}
function formatCurrency(num) {
return "$" + num.toFixed(2).replace(/\d(?=(\d{3})+\.)/g, '$&,');
}
// Run calculation on load for demo
window.onload = function() {
calculateRentalCashFlow();
};
Understanding Real Estate Investment Metrics
Investing in rental property is one of the most reliable ways to build long-term wealth, but success depends entirely on the numbers. Too often, new investors focus solely on the potential appreciation of the asset, ignoring the critical daily reality of cash flow. This Rental Property Cash Flow Calculator helps you analyze the viability of a potential investment deal before you sign on the dotted line.
What is Rental Cash Flow?
Cash flow is the net income from a real estate investment after mortgage payments and operating expenses have been made. It is essentially the "profit" you pocket every month.
The formula used in this calculator is:
- Gross Income: Your total monthly rental income.
- Minus Operating Expenses: Property taxes, insurance, HOA fees, maintenance, and vacancy provisions.
- Minus Debt Service: Your monthly principal and interest mortgage payment.
- Equals Cash Flow: The remaining money is your positive cash flow (profit) or negative cash flow (loss).
Why "Cash on Cash ROI" Matters
While cash flow tells you how much money you make per month, Cash on Cash Return on Investment (ROI) tells you how hard your money is working for you. It compares your annual pre-tax cash flow to the total cash invested (your down payment).
For example, if you invest $50,000 as a down payment and the property generates $5,000 in positive cash flow per year, your Cash on Cash ROI is 10%. This metric allows you to compare real estate returns directly against other investment vehicles like stocks or bonds.
Tips for Using This Calculator
To get the most accurate results, ensure you are realistic about your "Other Monthly Expenses." Do not just include taxes and insurance. You should also factor in:
- Maintenance & Repairs: Usually estimated at 5-10% of monthly rent.
- Vacancy Rate: The cost of the property sitting empty between tenants (typically 5-8%).
- Property Management: If you hire a manager, this can cost 8-10% of monthly rent.
Use this tool to run "what-if" scenarios. See how changing your down payment percentage affects your monthly cash flow, or determine the maximum purchase price you can afford while still maintaining a positive ROI.