.rental-calculator-container {
font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
max-width: 800px;
margin: 0 auto;
background: #fff;
padding: 20px;
border: 1px solid #e0e0e0;
border-radius: 8px;
box-shadow: 0 4px 10px rgba(0,0,0,0.05);
}
.rental-calc-header {
text-align: center;
margin-bottom: 30px;
}
.rental-calc-header h2 {
color: #2c3e50;
margin-bottom: 10px;
}
.rental-row {
display: flex;
flex-wrap: wrap;
margin: 0 -10px;
}
.rental-col {
flex: 1;
min-width: 300px;
padding: 0 10px;
margin-bottom: 20px;
}
.rental-input-group {
margin-bottom: 15px;
}
.rental-input-group label {
display: block;
margin-bottom: 5px;
font-weight: 600;
color: #555;
font-size: 14px;
}
.rental-input-group input {
width: 100%;
padding: 10px;
border: 1px solid #ddd;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
.rental-input-group input:focus {
border-color: #3498db;
outline: none;
}
.section-title {
color: #3498db;
border-bottom: 2px solid #f0f0f0;
padding-bottom: 5px;
margin-bottom: 15px;
font-size: 18px;
font-weight: bold;
}
.calc-btn {
display: block;
width: 100%;
padding: 15px;
background-color: #27ae60;
color: white;
border: none;
border-radius: 5px;
font-size: 18px;
font-weight: bold;
cursor: pointer;
transition: background 0.3s;
margin-top: 10px;
}
.calc-btn:hover {
background-color: #219150;
}
.results-box {
background-color: #f8f9fa;
border: 1px solid #e9ecef;
border-radius: 6px;
padding: 20px;
margin-top: 30px;
}
.result-row {
display: flex;
justify-content: space-between;
padding: 10px 0;
border-bottom: 1px dashed #ccc;
}
.result-row:last-child {
border-bottom: none;
}
.result-label {
color: #555;
font-weight: 500;
}
.result-value {
font-weight: 700;
color: #2c3e50;
}
.result-highlight {
color: #27ae60;
font-size: 1.2em;
}
.result-negative {
color: #c0392b;
}
.article-content {
margin-top: 40px;
line-height: 1.6;
color: #333;
}
.article-content h3 {
color: #2c3e50;
margin-top: 25px;
}
.article-content ul {
padding-left: 20px;
}
.article-content li {
margin-bottom: 10px;
}
function calculateRental() {
// 1. Get Inputs
var price = parseFloat(document.getElementById('purchasePrice').value) || 0;
var down = parseFloat(document.getElementById('downPayment').value) || 0;
var rate = parseFloat(document.getElementById('interestRate').value) || 0;
var term = parseFloat(document.getElementById('loanTerm').value) || 0;
var closing = parseFloat(document.getElementById('closingCosts').value) || 0;
var rent = parseFloat(document.getElementById('monthlyRent').value) || 0;
var taxYear = parseFloat(document.getElementById('propertyTax').value) || 0;
var insYear = parseFloat(document.getElementById('insurance').value) || 0;
var hoa = parseFloat(document.getElementById('hoa').value) || 0;
var vacRate = parseFloat(document.getElementById('vacancyRate').value) || 0;
var maintRate = parseFloat(document.getElementById('maintenanceRate').value) || 0;
var mgmtRate = parseFloat(document.getElementById('managementRate').value) || 0;
// 2. Calculations
// Loan Amount
var loanAmount = price – down;
// Monthly Mortgage (P&I)
// Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
var monthlyRate = (rate / 100) / 12;
var numPayments = term * 12;
var mortgage = 0;
if (loanAmount > 0 && monthlyRate > 0) {
mortgage = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, numPayments)) / (Math.pow(1 + monthlyRate, numPayments) – 1);
} else if (loanAmount > 0 && monthlyRate === 0) {
mortgage = loanAmount / numPayments;
}
// Monthly Income
var vacancyLoss = rent * (vacRate / 100);
var effectiveIncome = rent – vacancyLoss;
// Monthly Expenses
var taxMonth = taxYear / 12;
var insMonth = insYear / 12;
var maintCost = rent * (maintRate / 100);
var mgmtCost = rent * (mgmtRate / 100);
var totalOpEx = taxMonth + insMonth + hoa + maintCost + mgmtCost;
// Net Operating Income (Monthly)
var noiMonthly = effectiveIncome – totalOpEx;
var noiAnnual = noiMonthly * 12;
// Cash Flow
var cashFlow = noiMonthly – mortgage;
var cashFlowAnnual = cashFlow * 12;
// Investment Returns
var totalInvestment = down + closing;
var capRate = (price > 0) ? (noiAnnual / price) * 100 : 0;
var cocReturn = (totalInvestment > 0) ? (cashFlowAnnual / totalInvestment) * 100 : 0;
// 3. Update UI
// Helper for currency
var fmt = new Intl.NumberFormat('en-US', { style: 'currency', currency: 'USD' });
document.getElementById('resGrossRent').innerText = fmt.format(rent);
document.getElementById('resVacancy').innerText = "-" + fmt.format(vacancyLoss);
document.getElementById('resOpEx').innerText = "-" + fmt.format(totalOpEx);
document.getElementById('resNOI').innerText = fmt.format(noiMonthly);
document.getElementById('resMortgage').innerText = "-" + fmt.format(mortgage);
var cfElem = document.getElementById('resCashFlow');
cfElem.innerText = fmt.format(cashFlow);
if(cashFlow >= 0) {
cfElem.className = "result-value result-highlight";
cfElem.style.color = "#27ae60";
} else {
cfElem.className = "result-value result-negative";
cfElem.style.color = "#c0392b";
}
document.getElementById('resCapRate').innerText = capRate.toFixed(2) + "%";
document.getElementById('resCoC').innerText = cocReturn.toFixed(2) + "%";
document.getElementById('resTotalInvest').innerText = fmt.format(totalInvestment);
// Show results
document.getElementById('resultsSection').style.display = "block";
}
Rental Property Cash Flow Calculator
Analyze your real estate investment deal instantly.
Purchase & Financing
Income & Expenses
Monthly Cash Flow Analysis
Gross Monthly Rent:
Vacancy Loss:
Operating Expenses:
Net Operating Income (NOI):
Mortgage Payment (P&I):
Monthly Cash Flow:
Return on Investment (ROI)
Cap Rate:
Cash on Cash Return:
Total Initial Investment:
Understanding Your Rental Property Numbers
Successful real estate investing relies on accurate math, not gut feelings. This Rental Property Cash Flow Calculator helps you determine if a potential deal will put money in your pocket every month or become a financial liability.
Key Metrics Explained
- Net Operating Income (NOI): This is your total income (minus vacancy losses) minus all operating expenses. It represents the profitability of the property before factoring in the mortgage.
- Cash Flow: The net profit you take home after paying all expenses and the mortgage. Positive cash flow is essential for long-term sustainability.
- Cap Rate (Capitalization Rate): A measure of the property's natural rate of return. It is calculated by dividing the NOI by the property's purchase price. It helps compare properties regardless of financing.
- Cash on Cash Return: This metric shows the return on the actual cash you invested (down payment + closing costs). It is often considered the most important metric for investors using leverage.
How to Calculate Rental Cash Flow
The formula for cash flow is simple in theory but requires detailed inputs:
Cash Flow = (Gross Rent – Vacancy – Operating Expenses) – Mortgage Payment
Don't forget to account for "hidden" expenses like vacancy (months where the unit is empty), maintenance reserves (saving for a new roof or water heater), and property management fees if you choose not to be a landlord yourself.