Gross Income to Net Operating Income
Every real estate investment analysis starts with the income statement — a structured walkthrough from gross potential revenue down to the net operating income (NOI) that the property actually produces. Gross Potential Income (GPI) is the total annual rent the property would collect if every unit were occupied at full market rent for all 12 months. It is a theoretical ceiling, never an operational reality. From GPI, subtract the Vacancy and Credit Loss allowance — typically 5–10% in a stable market, higher in volatile markets or with a single-tenant property. A single-family rental with one tenant carries 100% vacancy risk when that tenant leaves; a 20-unit apartment spreads that risk. The result is Effective Gross Income (EGI): the realistic collected revenue. From EGI, subtract all Operating Expenses. These include property taxes, insurance, property management fees (typically 8–12% of collected rent), repairs and maintenance, landscaping, utilities paid by the owner, vacancy-driven turnover costs, and a capital expenditure (CapEx) reserve — money set aside for large future expenses like a roof replacement or HVAC system. What is NOT an operating expense: mortgage principal and interest payments. Financing costs are excluded from the NOI calculation deliberately — NOI is a property-level metric that measures the asset's intrinsic income-producing ability independent of how it is financed. This makes NOI comparable across properties regardless of their debt structure. Net Operating Income = EGI − Total Operating Expenses. A property with EGI of $48,000 and operating expenses of $18,000 has an NOI of $30,000. NOI is the fundamental input for every subsequent investment metric.