Net operating income (NOI) is a property’s revenue minus its operating expenses — before debt service, income taxes, capital expenditures, and depreciation. It is real estate’s core earnings measure: the numerator of every cap rate, the income lenders test coverage against, and the line where underwriting optimism does its quiet work.
The formula and its boundaries
NOI = effective gross income − operating expenses. Effective gross income starts with scheduled rents, subtracts vacancy and credit loss, and adds other income (parking, fees, reimbursements). Operating expenses include taxes, insurance, utilities, repairs and maintenance, and property management. Excluded by definition — and this is where the measure’s discipline lives: debt service (NOI is capital-structure-neutral, which is what makes cap rate comparisons possible), capital expenditures (roof replacements and tenant improvements live below the NOI line, which is why NOI overstates distributable cash), depreciation (non-cash), and income taxes.
NOI’s three jobs: valuation — value = NOI ÷ cap rate, so every dollar of NOI moves price by its multiple (at a 5-cap, $1 of NOI is $20 of value — the arithmetic behind both value-add strategies and expense-item fights); lending — DSCR divides NOI by debt payments, and loan sizing follows; performance — same-property NOI growth is the operating scoreboard of REITs and funds, stripped of acquisition effects.
Reading NOI skeptically is a core diligence skill, because the definition’s edges invite massage: pro forma NOI (projected rents, assumed lease-up) marketed as if achieved; management fees or reserves omitted from expenses; above-the-line treatment of items that belong below; and “adjusted” or “normalized” NOI whose adjustments deserve line-item review. The standard defenses: insist on trailing-twelve-month actuals beside any pro forma, reconcile the expense load against comparable properties (an expense ratio far below peers is a projection, not an achievement), and remember the capex gap — properties with heavy tenant-improvement and leasing-cost needs can show strong NOI and weak true cash flow simultaneously, which is precisely the distinction between NOI and the cash available for distributions.
FAQ
What is NOI in simple terms?
What a property earns from operations: rental and other income minus the costs of running the building — before any mortgage payments or big capital projects.
Is NOI the same as cash flow?
No — NOI excludes debt service and capital expenditures. A property’s actual distributable cash is NOI minus loan payments minus capex, which can be a much smaller number.
Why does NOI matter so much?
Because value and lending both key off it: price is NOI divided by the cap rate, and loan coverage is NOI divided by debt service — small NOI changes move both materially.
Related terms
Cap Rate · DSCR · Occupancy Rate · Cash-on-Cash Return · Loan-to-Value (LTV)
Educational content only; not investment, tax, or legal advice. Consult qualified professionals regarding your specific circumstances.
