function calculateCapRate() {
// Get Inputs
var priceInput = document.getElementById('propertyPrice');
var rentInput = document.getElementById('monthlyRentalIncome');
var expensesInput = document.getElementById('annualOperatingExpenses');
var vacancyInput = document.getElementById('vacancyRate');
var errorDiv = document.getElementById('errorMessage');
var resultBox = document.getElementById('resultsDisplay');
var price = parseFloat(priceInput.value);
var monthlyRent = parseFloat(rentInput.value);
var annualExpenses = parseFloat(expensesInput.value);
var vacancyRate = parseFloat(vacancyInput.value);
// Validation
if (isNaN(price) || isNaN(monthlyRent) || isNaN(annualExpenses) || isNaN(vacancyRate) || price <= 0) {
errorDiv.style.display = "block";
resultBox.style.display = "none";
return;
}
errorDiv.style.display = "none";
// Logic
// 1. Calculate Gross Annual Income
var grossAnnualIncome = monthlyRent * 12;
// 2. Calculate Vacancy Loss
var vacancyLoss = grossAnnualIncome * (vacancyRate / 100);
// 3. Calculate Effective Gross Income
var effectiveGrossIncome = grossAnnualIncome – vacancyLoss;
// 4. Calculate Net Operating Income (NOI)
var noi = effectiveGrossIncome – annualExpenses;
// 5. Calculate Cap Rate
var capRate = (noi / price) * 100;
// Display Results
document.getElementById('resGrossIncome').innerHTML = "$" + grossAnnualIncome.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('resEffectiveIncome').innerHTML = "$" + effectiveGrossIncome.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('resNOI').innerHTML = "$" + noi.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('resCapRate').innerHTML = capRate.toFixed(2) + "%";
resultBox.style.display = "block";
}
Understanding the Capitalization Rate (Cap Rate)
In commercial and residential real estate investing, the Capitalization Rate (or Cap Rate) is one of the most fundamental metrics used to evaluate the profitability and return potential of an investment property. It represents the rate of return on a real estate investment property based on the income that the property is expected to generate.
Unlike other metrics like Cash-on-Cash return, the Cap Rate assumes the property is purchased with all cash, allowing investors to compare properties directly without the variable of financing structures skewing the data.
How is Cap Rate Calculated?
The formula for Cap Rate is relatively straightforward, yet it relies on accurate data regarding the property's income and expenses. The formula used in the calculator above is:
Cap Rate = (Net Operating Income / Current Market Value) × 100
To derive the Net Operating Income (NOI), you must subtract all annual operating expenses (management fees, maintenance, insurance, taxes) from the effective gross income. Crucially, mortgage payments (debt service) are NOT included in operating expenses when calculating NOI for Cap Rate.
What is a "Good" Cap Rate?
There is no single percentage that defines a "good" Cap Rate, as it varies significantly by location, property class, and the current interest rate environment. However, general guidelines typically suggest:
4% – 5%: Often associated with low-risk properties in high-demand, Class A locations (e.g., downtown in a major city). These offer stability but lower immediate returns.
6% – 8%: A balanced target for many residential rental investors, offering a mix of reasonable income and potential appreciation.
8% – 12%: Higher risk, potentially older properties or those in declining neighborhoods. While the cash flow looks higher, the risk of vacancies and maintenance issues is also elevated.
When to Use This Calculator
Use this tool when you are in the initial stages of screening properties. If a seller lists a property at $500,000 claiming it generates $40,000 in NOI, the Cap Rate is 8%. If comparable properties in the area are selling at a 5% Cap Rate, the property might be undervalued (a good deal). Conversely, if the market average is 10%, the property is likely overpriced.