# Real Estate NOI: What Net Operating Income Is and How to Calculate It Published: 2026-02-21 Author: Warren Team URL: https://www.heywarren.com/blog/what-is-real-estate-noi --- [Net Operating Income](/blog/calculation-of-net-operating-income) (NOI) is the annual income generated by a real estate investment property after subtracting all operating expenses, but before deducting mortgage payments (debt service), income taxes, depreciation, and capital expenditures. NOI is the foundational metric in commercial real estate, it is used to determine property value (via cap rate), assess cash flow potential, underwrite loans, and compare investment alternatives. A property with $500,000 of gross rental income and $200,000 of operating expenses has an NOI of $300,000. Everything in real estate investment analysis, from cap rates to DSCR to property valuation, begins with NOI. ## The NOI Formula > **NOI = Gross Operating Income − Operating Expenses** ![How gross rental income flows down to Net Operating Income after vacancy and operating expenses.](data:image/svg+xml,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20viewBox%3D%220%200%20660%20125%22%20width%3D%22660%22%20height%3D%22125%22%20role%3D%22img%22%3E%3Ctitle%3EFlow%20diagram%3C%2Ftitle%3E%3Crect%20width%3D%22100%25%22%20height%3D%22100%25%22%20fill%3D%22%23f8fafc%22%2F%3E%3Crect%20x%3D%2230%22%20y%3D%2225%22%20width%3D%22170%22%20height%3D%2275%22%20rx%3D%2210%22%20fill%3D%22white%22%20stroke%3D%22%232563eb%22%20stroke-width%3D%222%22%2F%3E%3Ctext%20x%3D%22115%22%20y%3D%2258.5%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2214%22%20font-weight%3D%22600%22%20fill%3D%22%230f172a%22%3EPotential%20Gross%20Income%3C%2Ftext%3E%3Ctext%20x%3D%22115%22%20y%3D%2278.5%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2211%22%20fill%3D%22%2364748b%22%3E%24600%2C000%3C%2Ftext%3E%3Cline%20x1%3D%22205%22%20y1%3D%2262.5%22%20x2%3D%22237%22%20y2%3D%2262.5%22%20stroke%3D%22%2364748b%22%20stroke-width%3D%222%22%2F%3E%3Cpolygon%20points%3D%22244%2C62.5%20235%2C57.5%20235%2C67.5%22%20fill%3D%22%2364748b%22%2F%3E%3Crect%20x%3D%22245%22%20y%3D%2225%22%20width%3D%22170%22%20height%3D%2275%22%20rx%3D%2210%22%20fill%3D%22white%22%20stroke%3D%22%232563eb%22%20stroke-width%3D%222%22%2F%3E%3Ctext%20x%3D%22330%22%20y%3D%2258.5%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2214%22%20font-weight%3D%22600%22%20fill%3D%22%230f172a%22%3EGross%20Operating%20Income%3C%2Ftext%3E%3Ctext%20x%3D%22330%22%20y%3D%2278.5%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2211%22%20fill%3D%22%2364748b%22%3E%24570%2C000%3C%2Ftext%3E%3Cline%20x1%3D%22420%22%20y1%3D%2262.5%22%20x2%3D%22452%22%20y2%3D%2262.5%22%20stroke%3D%22%2364748b%22%20stroke-width%3D%222%22%2F%3E%3Cpolygon%20points%3D%22459%2C62.5%20450%2C57.5%20450%2C67.5%22%20fill%3D%22%2364748b%22%2F%3E%3Crect%20x%3D%22460%22%20y%3D%2225%22%20width%3D%22170%22%20height%3D%2275%22%20rx%3D%2210%22%20fill%3D%22white%22%20stroke%3D%22%232563eb%22%20stroke-width%3D%222%22%2F%3E%3Ctext%20x%3D%22545%22%20y%3D%2258.5%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2214%22%20font-weight%3D%22600%22%20fill%3D%22%230f172a%22%3ENet%20Operating%20Income%3C%2Ftext%3E%3Ctext%20x%3D%22545%22%20y%3D%2278.5%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2211%22%20fill%3D%22%2364748b%22%3E%24404%2C400%3C%2Ftext%3E%3C%2Fsvg%3E) *How gross rental income flows down to Net Operating Income after vacancy and operating expenses.* Where: > **Gross Operating Income (GOI) = Potential Gross Income − Vacancy & Credit Loss** **Full calculation breakdown**: | Line Item | Example | |---|---| | **Potential Gross Income (PGI)** | $600,000 | | Less: Vacancy & Credit Loss (5%) | −$30,000 | | **Gross Operating Income (GOI)** | $570,000 | | Less: Property Management (8%) | −$45,600 | | Less: Insurance | −$18,000 | | Less: Property Taxes | −$42,000 | | Less: Maintenance & Repairs | −$25,000 | | Less: Utilities (common areas) | −$12,000 | | Less: Landscaping/Janitorial | −$8,000 | | Less: Reserves for Replacement | −$15,000 | | **Net Operating Income (NOI)** | **$404,400** | ## What Is Included in Operating Expenses? Operating expenses are the regular, recurring costs of owning and operating the property: - Property management fees (typically 6%–10% of collected rents for residential; 3%–6% for commercial) - Property taxes - Insurance (hazard, liability) - Repairs and maintenance - Utilities (if paid by owner, common areas, water/sewer for multi-family) - Common area maintenance (CAM) costs - Pest control, landscaping, snow removal - Reserves for replacement (annual set-aside for future capital items) - Administrative costs ![The recurring costs deducted from gross income to arrive at NOI.](data:image/svg+xml,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20viewBox%3D%220%200%20760%20211%22%20width%3D%22760%22%20height%3D%22211%22%20role%3D%22img%22%3E%3Ctitle%3EHierarchy%3C%2Ftitle%3E%3Crect%20width%3D%22100%25%22%20height%3D%22100%25%22%20fill%3D%22%23f8fafc%22%2F%3E%3Crect%20x%3D%22300%22%20y%3D%2220%22%20width%3D%22160%22%20height%3D%2258%22%20rx%3D%228%22%20fill%3D%22%232563eb%22%2F%3E%3Ctext%20x%3D%22380%22%20y%3D%2254%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2214%22%20font-weight%3D%22700%22%20fill%3D%22white%22%3EOperating%20Expenses%3C%2Ftext%3E%3Cpath%20d%3D%22M%20380%2078%20L%20380%20105.5%20L%20110%20105.5%20L%20110%20133%22%20stroke%3D%22%23cbd5e1%22%20stroke-width%3D%222%22%20fill%3D%22none%22%2F%3E%3Crect%20x%3D%2230%22%20y%3D%22133%22%20width%3D%22160%22%20height%3D%2258%22%20rx%3D%228%22%20fill%3D%22white%22%20stroke%3D%22%230891b2%22%20stroke-width%3D%222%22%2F%3E%3Ctext%20x%3D%22110%22%20y%3D%22158%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2213%22%20font-weight%3D%22600%22%20fill%3D%22%230f172a%22%3EProperty%20Mgmt%3C%2Ftext%3E%3Ctext%20x%3D%22110%22%20y%3D%22176%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2210%22%20fill%3D%22%2364748b%22%3E6%E2%80%9310%25%20of%20rents%3C%2Ftext%3E%3Cpath%20d%3D%22M%20380%2078%20L%20380%20105.5%20L%20290%20105.5%20L%20290%20133%22%20stroke%3D%22%23cbd5e1%22%20stroke-width%3D%222%22%20fill%3D%22none%22%2F%3E%3Crect%20x%3D%22210%22%20y%3D%22133%22%20width%3D%22160%22%20height%3D%2258%22%20rx%3D%228%22%20fill%3D%22white%22%20stroke%3D%22%230891b2%22%20stroke-width%3D%222%22%2F%3E%3Ctext%20x%3D%22290%22%20y%3D%22167%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2213%22%20font-weight%3D%22600%22%20fill%3D%22%230f172a%22%3ETaxes%20%26amp%3B%20Insurance%3C%2Ftext%3E%3Cpath%20d%3D%22M%20380%2078%20L%20380%20105.5%20L%20470%20105.5%20L%20470%20133%22%20stroke%3D%22%23cbd5e1%22%20stroke-width%3D%222%22%20fill%3D%22none%22%2F%3E%3Crect%20x%3D%22390%22%20y%3D%22133%22%20width%3D%22160%22%20height%3D%2258%22%20rx%3D%228%22%20fill%3D%22white%22%20stroke%3D%22%230891b2%22%20stroke-width%3D%222%22%2F%3E%3Ctext%20x%3D%22470%22%20y%3D%22167%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2213%22%20font-weight%3D%22600%22%20fill%3D%22%230f172a%22%3ERepairs%20%26amp%3B%20Utilities%3C%2Ftext%3E%3Cpath%20d%3D%22M%20380%2078%20L%20380%20105.5%20L%20650%20105.5%20L%20650%20133%22%20stroke%3D%22%23cbd5e1%22%20stroke-width%3D%222%22%20fill%3D%22none%22%2F%3E%3Crect%20x%3D%22570%22%20y%3D%22133%22%20width%3D%22160%22%20height%3D%2258%22%20rx%3D%228%22%20fill%3D%22white%22%20stroke%3D%22%230891b2%22%20stroke-width%3D%222%22%2F%3E%3Ctext%20x%3D%22650%22%20y%3D%22158%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2213%22%20font-weight%3D%22600%22%20fill%3D%22%230f172a%22%3EReserves%3C%2Ftext%3E%3Ctext%20x%3D%22650%22%20y%3D%22176%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2210%22%20fill%3D%22%2364748b%22%3EReplacement%20fund%3C%2Ftext%3E%3C%2Fsvg%3E) *The recurring costs deducted from gross income to arrive at NOI.* **NOT included in operating expenses** (below NOI): - Mortgage principal and interest (debt service) - Income taxes - Depreciation (non-cash) - Capital expenditures (roof replacement, major renovations) - Leasing commissions and tenant improvement allowances (sometimes) ## NOI and Cap Rate Valuation The **[capitalisation rate](/blog/cap-rate-real-estate) (cap rate)** converts NOI directly into property value: > **Property Value = NOI ÷ Cap Rate** **Example**: - NOI: $404,400 - Market cap rate for similar properties: 5.5% - Implied property value: $404,400 / 0.055 = **$7,352,727** Cap rates reflect market conditions and risk: lower cap rates = higher valuations (expensive markets, lower risk); higher cap rates = lower valuations (higher risk, less desirable markets). **Cap rate example by market**: - Class A office in NYC/San Francisco: 4.0%–5.0% - Multi-family in major MSA: 4.5%–5.5% - Retail strip centre in secondary market: 6.5%–8.0% - Industrial (flex) in tertiary market: 6.0%–7.5% Increasing NOI by 10% (through rent increases or expense reductions) increases property value by 10% at the same cap rate, a direct one-to-one relationship. ## NOI and Debt Service Coverage Ratio (DSCR) Lenders use NOI to underwrite real estate loans via the DSCR: > **DSCR = NOI ÷ Annual Debt Service** - DSCR > 1.0x: NOI covers debt service with margin - DSCR = 1.0x: NOI exactly covers debt service (no cushion) - DSCR < 1.0x: NOI insufficient to cover debt service (negative coverage) Most commercial mortgage lenders require DSCR of 1.20x–1.35x: **Example**: - NOI: $404,400 - Annual debt service (P+I): $280,000 - DSCR: $404,400 / $280,000 = **1.44x** (well-covered) A lender may also use the DSCR to size the loan: maximum loan = NOI / (required DSCR × mortgage constant). ## NOI vs. Cash Flow NOI is **not** the same as cash flow to the owner: ![NOI of $404,400 versus the $124,400 pre-tax cash flow the owner actually receives after debt service.](data:image/svg+xml,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20viewBox%3D%220%200%20800%20210%22%20width%3D%22800%22%20height%3D%22210%22%20role%3D%22img%22%3E%3Ctitle%3EComparison%3C%2Ftitle%3E%3Crect%20width%3D%22100%25%22%20height%3D%22100%25%22%20fill%3D%22%23f8fafc%22%2F%3E%3Ctext%20x%3D%22230%22%20y%3D%2257.5%22%20text-anchor%3D%22end%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2214%22%20font-weight%3D%22600%22%20fill%3D%22%230f172a%22%3ENOI%3C%2Ftext%3E%3Crect%20x%3D%22240%22%20y%3D%2225%22%20width%3D%22450%22%20height%3D%2255%22%20rx%3D%226%22%20fill%3D%22%232563eb%22%2F%3E%3Ctext%20x%3D%22702%22%20y%3D%2257.5%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2214%22%20font-weight%3D%22700%22%20fill%3D%22%232563eb%22%3E%24404K%3C%2Ftext%3E%3Ctext%20x%3D%22230%22%20y%3D%22152.5%22%20text-anchor%3D%22end%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2214%22%20font-weight%3D%22600%22%20fill%3D%22%230f172a%22%3ECash%20Flow%3C%2Ftext%3E%3Crect%20x%3D%22240%22%20y%3D%22120%22%20width%3D%22138.42729970326408%22%20height%3D%2255%22%20rx%3D%226%22%20fill%3D%22%237c3aed%22%2F%3E%3Ctext%20x%3D%22390.4272997032641%22%20y%3D%22152.5%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2214%22%20font-weight%3D%22700%22%20fill%3D%22%237c3aed%22%3E%24124K%3C%2Ftext%3E%3C%2Fsvg%3E) *NOI of $404,400 versus the $124,400 pre-tax cash flow the owner actually receives after debt service.* > **Cash Flow Before Tax = NOI − Debt Service** > **Cash Flow After Tax = Cash Flow Before Tax ± Tax Benefits (depreciation)** A property with $404,400 NOI and $280,000 debt service produces **$124,400 in pre-tax cash flow**, what actually reaches the owner's pocket. Cash flow can be positive even when the property is slightly underwater on an accounting basis (due to non-cash depreciation deductions). ## Common NOI Mistakes **Omitting vacancy**: Using 100% occupancy rather than stabilised (market) vacancy overstates NOI and inflates valuations. **Missing reserves**: Omitting replacement reserves (for roof, HVAC, appliances) understates true operating costs. **Using projected NOI**: Buyers should scrutinise "pro forma" NOI (seller's projections) vs. in-place NOI (actual trailing 12 months). Deals underwritten to pro forma NOI that never materialises are a common source of real estate losses. **Including non-operating income**: One-time lease termination payments or insurance proceeds are not recurring operating income and should be excluded from NOI for valuation purposes. ## Authoritative Sources For deeper background and primary-source data on this topic, the following authoritative sources are useful starting points: - [IRS](https://www.irs.gov/) - [SEC](https://www.sec.gov/) ## Conclusion NOI is the single most important number in commercial real estate, it determines property value through cap rate, supports loan underwriting through DSCR, and drives cash flow to investors. Accurate NOI calculation requires proper treatment of vacancy, all recurring operating expenses, and replacement reserves. The gap between in-place NOI and pro forma NOI is where real estate investments succeed or fail. For related commercial real estate finance concepts, see our guides on [loan-to-cost meaning](/blog/loan-to-cost-meaning) and [triple net lease](/blog/triple-net-lease). Warren at [heywarren.com](https://heywarren.com) helps real estate investors, property owners, and analysts calculate NOI accurately, apply cap rates for valuation, and underwrite commercial real estate transactions. --- ## Related Reading **More from Warren**: - [Loan-to-Cost (LTC): What It Means in Real Estate Finance](/blog/loan-to-cost-meaning) - [Triple Net Lease (NNN): What It Is and How It Works](/blog/triple-net-lease) - [Modified Gross Lease: What It Is and How It Works in Commercial Real Estate](/blog/modified-gross-leases) **Authoritative sources**: - [Fannie Mae, Multifamily Underwriting](https://www.fanniemae.com/multifamily) - [Urban Land Institute, Real Estate Finance](https://uli.org/research/) - [CCIM Institute, Investment Analysis](https://www.ccim.com/education/)