Rental Property Cash Flow Calculator
body {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
line-height: 1.6;
color: #333;
max-width: 1200px;
margin: 0 auto;
padding: 20px;
background-color: #f9f9f9;
}
.calc-container {
background: #fff;
border-radius: 8px;
box-shadow: 0 4px 6px rgba(0,0,0,0.1);
padding: 30px;
margin-bottom: 40px;
display: flex;
flex-wrap: wrap;
gap: 30px;
}
.calc-inputs {
flex: 1;
min-width: 300px;
}
.calc-results {
flex: 1;
min-width: 300px;
background-color: #f0f7ff;
border-radius: 8px;
padding: 25px;
border: 1px solid #dbeafe;
}
h1, h2, h3 {
color: #2c3e50;
margin-top: 0;
}
.input-group {
margin-bottom: 15px;
}
.input-group label {
display: block;
margin-bottom: 5px;
font-weight: 600;
font-size: 0.9rem;
}
.input-group input {
width: 100%;
padding: 10px;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 1rem;
box-sizing: border-box; /* Fix padding issue */
}
.input-group input:focus {
border-color: #007bff;
outline: none;
}
.row {
display: flex;
gap: 15px;
}
.col-6 {
flex: 1;
}
button.calc-btn {
background-color: #007bff;
color: white;
border: none;
padding: 12px 20px;
border-radius: 4px;
cursor: pointer;
font-size: 1rem;
font-weight: bold;
width: 100%;
margin-top: 10px;
transition: background-color 0.2s;
}
button.calc-btn:hover {
background-color: #0056b3;
}
.result-item {
display: flex;
justify-content: space-between;
margin-bottom: 15px;
border-bottom: 1px solid #cbd5e1;
padding-bottom: 5px;
}
.result-item.final {
border-bottom: none;
margin-top: 20px;
font-size: 1.2rem;
font-weight: bold;
color: #007bff;
padding-top: 10px;
border-top: 2px solid #007bff;
}
.result-label {
color: #64748b;
}
.result-value {
font-weight: 700;
color: #1e293b;
}
.error-msg {
color: red;
font-size: 0.9rem;
display: none;
margin-top: 10px;
}
.article-section {
background: #fff;
padding: 40px;
border-radius: 8px;
box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}
.article-section h2 {
border-bottom: 2px solid #007bff;
padding-bottom: 10px;
margin-bottom: 20px;
}
.article-section ul {
padding-left: 20px;
}
.article-section li {
margin-bottom: 10px;
}
@media (max-width: 768px) {
.calc-container {
flex-direction: column;
}
}
Investment Analysis
Monthly Mortgage (P&I):
$0.00
Total Monthly Expenses:
$0.00
Net Operating Income (Monthly):
$0.00
Monthly Cash Flow:
$0.00
Annual Cash Flow:
$0.00
ROI Metrics
Cap Rate:
0.00%
Cash on Cash Return:
0.00%
Rental Property Cash Flow Calculator
Investing in real estate is a powerful way to build wealth, but the success of any rental property hinges on the numbers. This Rental Property Cash Flow Calculator helps investors determine the viability of an investment by calculating the estimated monthly cash flow, Capitalization Rate (Cap Rate), and Cash on Cash Return.
How to Use This Calculator
To get the most accurate results, input the specific details of the property you are analyzing:
- Purchase Price & Down Payment: The total cost of the property and the cash you are investing upfront.
- Loan Details: Your interest rate and the length of the mortgage (usually 30 years).
- Rental Income: The conservative estimate of monthly rent you can charge.
- Operating Expenses: Don't forget hidden costs like vacancy (periods without tenants) and maintenance reserves (saving for future repairs).
Understanding the Results
Monthly Cash Flow
This is the profit remaining after all expenses and mortgage payments are made. Positive cash flow means the property is putting money in your pocket every month. Negative cash flow implies the property costs you money to hold, which is a significant risk for investors.
Cap Rate (Capitalization Rate)
The Cap Rate measures the property's natural rate of return without factoring in mortgage financing. It is calculated by dividing the Net Operating Income (NOI) by the property's purchase price. A higher cap rate generally indicates a better potential return, though it may come with higher risk.
Formula: Cap Rate = (Net Operating Income / Purchase Price) × 100
Cash on Cash Return
This metric is crucial for leveraged investors. It compares your annual pre-tax cash flow to the total amount of cash you actually invested (down payment + closing costs). It tells you how hard your specific dollars are working.
Example: If you invest $50,000 and make $5,000 a year in profit, your Cash on Cash return is 10%.
Common Rules of Thumb
- The 1% Rule: Many investors look for properties where the monthly rent is at least 1% of the purchase price. (e.g., A $100,000 home should rent for $1,000).
- 50% Rule: A quick estimation that assumes 50% of rental income will go toward operating expenses (excluding the mortgage).
Use this calculator as a preliminary screening tool before diving deeper into due diligence for your next real estate investment.
function calculateRental() {
// 1. Get Values
var purchasePrice = parseFloat(document.getElementById('purchasePrice').value);
var downPayment = parseFloat(document.getElementById('downPayment').value);
var interestRate = parseFloat(document.getElementById('interestRate').value);
var loanTerm = parseFloat(document.getElementById('loanTerm').value);
var monthlyRent = parseFloat(document.getElementById('monthlyRent').value);
var propertyTaxYearly = parseFloat(document.getElementById('propertyTax').value);
var insuranceYearly = parseFloat(document.getElementById('insurance').value);
var hoaMonthly = parseFloat(document.getElementById('hoa').value);
var vacancyRate = parseFloat(document.getElementById('vacancyRate').value);
var maintenanceRate = parseFloat(document.getElementById('maintenanceRate').value);
var errorBox = document.getElementById('errorBox');
// 2. Validation
if (isNaN(purchasePrice) || isNaN(downPayment) || isNaN(interestRate) ||
isNaN(loanTerm) || isNaN(monthlyRent) || isNaN(propertyTaxYearly) ||
isNaN(insuranceYearly) || isNaN(hoaMonthly) || isNaN(vacancyRate) ||
isNaN(maintenanceRate)) {
errorBox.style.display = 'block';
return;
} else {
errorBox.style.display = 'none';
}
// 3. Loan Calculations
var loanAmount = purchasePrice – downPayment;
var monthlyInterest = interestRate / 100 / 12;
var numberOfPayments = loanTerm * 12;
var monthlyMortgage = 0;
if (loanAmount > 0 && interestRate > 0) {
monthlyMortgage = loanAmount * (monthlyInterest * Math.pow(1 + monthlyInterest, numberOfPayments)) / (Math.pow(1 + monthlyInterest, numberOfPayments) – 1);
} else if (loanAmount > 0 && interestRate === 0) {
monthlyMortgage = loanAmount / numberOfPayments;
}
// 4. Expense Calculations
var monthlyTax = propertyTaxYearly / 12;
var monthlyInsurance = insuranceYearly / 12;
var monthlyVacancyCost = monthlyRent * (vacancyRate / 100);
var monthlyMaintenanceCost = monthlyRent * (maintenanceRate / 100);
// Operating Expenses (Tax, Ins, HOA, Vacancy, Maint) – Does NOT include mortgage
var monthlyOperatingExpenses = monthlyTax + monthlyInsurance + hoaMonthly + monthlyVacancyCost + monthlyMaintenanceCost;
// Total Expenses (Operating + Mortgage)
var totalMonthlyExpenses = monthlyOperatingExpenses + monthlyMortgage;
// 5. Income Metrics
var monthlyNOI = monthlyRent – monthlyOperatingExpenses;
var monthlyCashFlow = monthlyRent – totalMonthlyExpenses;
var annualCashFlow = monthlyCashFlow * 12;
var annualNOI = monthlyNOI * 12;
// 6. ROI Metrics
var capRate = 0;
if (purchasePrice > 0) {
capRate = (annualNOI / purchasePrice) * 100;
}
var cashOnCash = 0;
// Total cash invested is generally Down Payment + Closing Costs.
// For this simple calculator, we assume Cash Invested = Down Payment.
if (downPayment > 0) {
cashOnCash = (annualCashFlow / downPayment) * 100;
}
// 7. Format and Display Results
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
});
document.getElementById('resMortgage').innerText = formatter.format(monthlyMortgage);
document.getElementById('resExpenses').innerText = formatter.format(totalMonthlyExpenses);
document.getElementById('resNOI').innerText = formatter.format(monthlyNOI);
var cfElement = document.getElementById('resCashFlow');
cfElement.innerText = formatter.format(monthlyCashFlow);
if(monthlyCashFlow >= 0) {
cfElement.style.color = '#16a34a'; // Green
} else {
cfElement.style.color = '#dc2626'; // Red
}
var annualCfElement = document.getElementById('resAnnualCashFlow');
annualCfElement.innerText = formatter.format(annualCashFlow);
if(annualCashFlow >= 0) {
annualCfElement.style.color = '#16a34a';
} else {
annualCfElement.style.color = '#dc2626';
}
document.getElementById('resCapRate').innerText = capRate.toFixed(2) + '%';
var cocElement = document.getElementById('resCoC');
cocElement.innerText = cashOnCash.toFixed(2) + '%';
if(cashOnCash >= 0) {
cocElement.style.color = '#16a34a';
} else {
cocElement.style.color = '#dc2626';
}
}
// Run calculation on load to show initial valid state
window.onload = function() {
calculateRental();
};