.calculator-container {
font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
max-width: 800px;
margin: 0 auto;
background: #fff;
padding: 20px;
border-radius: 8px;
box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}
.calc-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
}
@media (max-width: 600px) {
.calc-grid {
grid-template-columns: 1fr;
}
}
.input-group {
margin-bottom: 15px;
}
.input-group label {
display: block;
margin-bottom: 5px;
font-weight: 600;
color: #333;
}
.input-group input, .input-group select {
width: 100%;
padding: 10px;
border: 1px solid #ddd;
border-radius: 4px;
box-sizing: border-box;
font-size: 16px;
}
.input-group .suffix {
position: absolute;
right: 10px;
top: 38px;
color: #888;
}
.calc-btn {
background-color: #2c3e50;
color: white;
border: none;
padding: 15px 30px;
font-size: 18px;
border-radius: 4px;
cursor: pointer;
width: 100%;
margin-top: 20px;
transition: background 0.3s;
}
.calc-btn:hover {
background-color: #34495e;
}
.results-section {
margin-top: 30px;
background-color: #f8f9fa;
padding: 20px;
border-radius: 8px;
border-left: 5px solid #27ae60;
display: none;
}
.result-row {
display: flex;
justify-content: space-between;
padding: 10px 0;
border-bottom: 1px solid #e9ecef;
}
.result-row:last-child {
border-bottom: none;
}
.result-label {
font-weight: 500;
color: #555;
}
.result-value {
font-weight: 700;
color: #2c3e50;
}
.highlight-result {
font-size: 1.2em;
color: #27ae60;
}
.negative-flow {
color: #c0392b;
}
.calc-article {
margin-top: 40px;
line-height: 1.6;
color: #444;
}
.calc-article h2 {
color: #2c3e50;
margin-top: 30px;
}
.calc-article ul {
padding-left: 20px;
}
.calc-article li {
margin-bottom: 10px;
}
function calculateCashFlow() {
// Get Input Values
var price = parseFloat(document.getElementById('rp_price').value) || 0;
var downPercent = parseFloat(document.getElementById('rp_down').value) || 0;
var interestRate = parseFloat(document.getElementById('rp_rate').value) || 0;
var termYears = parseFloat(document.getElementById('rp_term').value) || 30;
var closingCosts = parseFloat(document.getElementById('rp_closing').value) || 0;
var monthlyRent = parseFloat(document.getElementById('rp_rent').value) || 0;
var annualTax = parseFloat(document.getElementById('rp_tax').value) || 0;
var annualInsurance = parseFloat(document.getElementById('rp_insurance').value) || 0;
var monthlyHOA = parseFloat(document.getElementById('rp_hoa').value) || 0;
var maintVacancyPercent = parseFloat(document.getElementById('rp_maintenance').value) || 0;
// Calculations
var downPaymentAmount = price * (downPercent / 100);
var loanAmount = price – downPaymentAmount;
// Mortgage Calculation (P&I)
var monthlyRate = (interestRate / 100) / 12;
var numberOfPayments = termYears * 12;
var monthlyMortgage = 0;
if (interestRate > 0) {
monthlyMortgage = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, numberOfPayments)) / (Math.pow(1 + monthlyRate, numberOfPayments) – 1);
} else {
monthlyMortgage = loanAmount / numberOfPayments;
}
// Monthly Expenses
var monthlyTax = annualTax / 12;
var monthlyInsurance = annualInsurance / 12;
var monthlyMaintVacancy = monthlyRent * (maintVacancyPercent / 100);
var monthlyOperatingExpenses = monthlyTax + monthlyInsurance + monthlyHOA + monthlyMaintVacancy;
var totalMonthlyCosts = monthlyMortgage + monthlyOperatingExpenses;
// Cash Flow
var monthlyCashFlow = monthlyRent – totalMonthlyCosts;
var annualCashFlow = monthlyCashFlow * 12;
// Annual Metrics
var annualIncome = monthlyRent * 12;
var annualOperatingExpenses = monthlyOperatingExpenses * 12;
var noi = annualIncome – annualOperatingExpenses;
var totalInvestment = downPaymentAmount + closingCosts;
var capRate = (price > 0) ? (noi / price) * 100 : 0;
var cashOnCash = (totalInvestment > 0) ? (annualCashFlow / totalInvestment) * 100 : 0;
// Display Results
document.getElementById('res_mortgage').innerText = formatCurrency(monthlyMortgage);
document.getElementById('res_expenses').innerText = formatCurrency(monthlyOperatingExpenses);
document.getElementById('res_total_cost').innerText = formatCurrency(totalMonthlyCosts);
var cfElement = document.getElementById('res_cashflow');
cfElement.innerText = formatCurrency(monthlyCashFlow);
if(monthlyCashFlow < 0) {
cfElement.classList.add('negative-flow');
cfElement.style.color = '#c0392b';
} else {
cfElement.classList.remove('negative-flow');
cfElement.style.color = '#27ae60';
}
document.getElementById('res_noi').innerText = formatCurrency(noi);
document.getElementById('res_cap').innerText = capRate.toFixed(2) + "%";
var cocElement = document.getElementById('res_coc');
cocElement.innerText = cashOnCash.toFixed(2) + "%";
if(cashOnCash < 0) {
cocElement.style.color = '#c0392b';
} else {
cocElement.style.color = '#2c3e50';
}
// Show results div
document.getElementById('rp_results').style.display = 'block';
}
function formatCurrency(num) {
return '$' + num.toFixed(2).replace(/\d(?=(\d{3})+\.)/g, '$&,');
}
Rental Property Cash Flow Calculator
Purchase Info
30 Years
15 Years
Income & Expenses
Monthly Financial Overview
Monthly Mortgage (P&I):
$0.00
Monthly Operating Expenses:
$0.00
Total Monthly Costs:
$0.00
Net Monthly Cash Flow:
$0.00
Annual Investment Returns
Net Operating Income (NOI):
$0.00
Cap Rate:
0.00%
Cash on Cash Return:
0.00%
Understanding Rental Property Cash Flow
Analyzing a rental property investment goes beyond just looking at the purchase price and rental income. To truly understand if a property is a good investment, you must calculate its cash flow and return on investment metrics. This Rental Property Cash Flow Calculator helps investors evaluate the profitability of a potential real estate deal.
What is Cash Flow?
Cash flow is the net amount of money moving into and out of your rental business. Positive cash flow means your monthly rental income exceeds all your monthly expenses, including the mortgage, taxes, insurance, and maintenance. Negative cash flow indicates that the property costs more to operate than it generates in rent, requiring you to pay out of pocket to keep it.
The formula is simple: Cash Flow = Total Rental Income – Total Expenses.
Key Metrics Explained
- NOI (Net Operating Income): This represents the annual profitability of the property before mortgage payments are deducted. It is calculated by subtracting operating expenses (taxes, insurance, maintenance, HOA) from the total income. It measures the property's potential income regardless of how it is financed.
- Cap Rate (Capitalization Rate): The Cap Rate is a fundamental metric used to estimate the return on investment for a property if you paid all cash. It is calculated as (NOI / Purchase Price) × 100. A higher cap rate generally indicates a better return, though it may come with higher risk.
- Cash on Cash Return (CoC): This measures the cash income earned on the cash invested. Unlike Cap Rate, CoC takes your financing into account. It is calculated as (Annual Pre-Tax Cash Flow / Total Cash Invested) × 100. This is often considered the most important metric for investors using leverage (mortgages).
Common Expenses to Consider
Many new investors make the mistake of underestimating expenses. When using this calculator, ensure you account for:
- Vacancy Rate: Properties won't be occupied 365 days a year. It's prudent to set aside 5-10% of monthly rent to cover periods between tenants.
- Maintenance & Repairs: Even new homes require upkeep. Setting aside 10-15% of the rent for repairs (leaky faucets, roof issues, painting) ensures your cash flow calculations are realistic.
- Property Management: If you hire a professional manager, they typically charge 8-10% of the monthly rent. Add this to your expenses if you don't plan to self-manage.
How to Use This Calculator
Start by entering the Purchase Price and your financing details, including Down Payment and Interest Rate. Be sure to include an estimate for Closing Costs, as this affects your total cash invested.
Next, input the expected Monthly Rental Income and all associated expenses. If you don't know the exact property tax or insurance, general estimates (usually 1-2% of property value for taxes) can serve as placeholders, but verifying with local data is best.
Once calculated, review the Net Monthly Cash Flow to see if the property puts money in your pocket every month, and check the Cash on Cash Return to see how hard your invested capital is working for you.