Cap Rate Calculator - Real Estate NOI Return

The cap rate calculator measures the unlevered income return on a rental property or commercial real estate acquisition. Investors use capitalization rate to compare buildings with different prices, rents, and operating expense structures before considering financing. The inputs focus on annual gross income, operating expenses, property value, and a vacancy allowance so the result reflects net operating income rather than headline rent. The calculation first reduces scheduled income by the vacancy percentage to estimate effective gross income. It then subtracts annual operating expenses to calculate net operating income, or NOI. The formula is: cap rate = (annual gross income x (1 - vacancy rate) - annual operating expenses) / property value x 100. The result card also shows a value implied by a 6% cap rate, which is a quick sensitivity check for how market yield assumptions translate into price. Cap rate is especially helpful when screening multifamily, office, retail, or single-family rental deals because it separates property operations from the buyer's loan terms. Two buyers may have different interest rates and down payments, but the same property NOI and value produce the same cap rate. That makes the metric useful for acquisition memos, broker conversations, and sanity-checking whether rent growth assumptions are doing too much work. The calculator does not include mortgage payments, income taxes, capital expenditures, leasing commissions, tenant improvements, or appreciation. It also depends heavily on clean NOI inputs: underestimating maintenance or vacancy can make a weak deal look attractive. For underwriting, compare the output with trailing financials, rent rolls, tax bills, insurance quotes, and a reserve budget before making an offer. For best results, keep all inputs on the same time basis and currency basis, then save the assumptions beside the output. That practice makes the estimate easier to audit later and prevents a common spreadsheet error: mixing monthly values with annual values or combining before-tax and after-tax figures. Re-run the scenario with conservative and optimistic assumptions before using the result in a budget, filing decision, trade review, or transaction memo.