FINANCIAL MODELING
NOI Calculator and Formula: Net Operating Income for Commercial Real Estate (Line-by-Line)
Calculate Your NOI
Defaults model a 180-unit garden multifamily property in Phoenix, the same worked example used across the Apers Learn valuation cluster. Edit any cell to compute against your own deal.
Revenue
Operating Expenses
Annual, $Asset Class
For opex-ratio benchmarkBroker NOI vs. Institutional NOI
Broker offering memoranda normalize differently than institutional underwriting. This panel takes the NOI you entered as the broker basis, applies a standard set of institutional adjustments, and shows the resulting gap. Management fee adjustments move NOI; reserves move cash flow after reserves (NCF), so the institutional column is labeled NCF. Toggle the adjustments to mirror the assumptions in your OM.
For multifamily NOI specifically (rent roll normalization, RUBS treatment, payroll allocation), see AQ-110, the Multifamily Acquisition Pocket Model →
BUILD IT IN APERS
Apers builds the full institutional NOI from T-12 normalization, line by line, every adjustment auditable, reserves shown separately below NOI. Try Apers free →
Or start in a pocket model: AQ-110 (multifamily) → · AQ-301 (anchored retail) → · AQ-401 (industrial) →
Key Takeaways
- NOI = Effective Gross Income − Operating Expenses. EGI is gross potential revenue net of vacancy and credit loss, plus other income. OpEx is the full nine-line institutional stack: tax, insurance, repairs, management, utilities, payroll, marketing, professional services, and G&A.
- Broker NOI and institutional underwriting are not the same number. Management fee normalization changes NOI; reserves change the cash flow a lender underwrites. In the worked example the two together move $1,366,500 to $1,302,905, a $63,595 gap, or 23 bps of cap-rate movement at a fixed $27.3M price. The calculator surfaces both side by side.
- Replacement reserves sit BELOW the NOI line on this page (illustrative levels: $300–$400/unit/year for multifamily, $0.20–$0.40/SF/year for office and retail). Deducting them gives cash flow after reserves, not NOI. Mixing the two makes your cap rate non-comparable to comp data.
- Insurance and property tax need current-market figures, not in-place ones.Florida reassesses to just value after a change of ownership; Arizona's limited property value can rise at most 5% a year over the prior year's limited value. Check the rules for your state before carrying the seller's tax line forward.
- Worked example: 180-unit Phoenix multifamily. $2.7M PGR + $135K other − 5.5% vacancy = $2,686,500 EGI. $1,320,000 of OpEx. NOI = $1,366,500 as entered. Applying the institutional adjustments (a $595 management-fee true-up and $63,000 of reserves at $350/unit) gives $1,302,905 of cash flow after reserves, a $63,595 gap (4.7% of the entered NOI).
Net Operating Income (NOI) is the most consequential line on a commercial real-estate operating statement. It is the numerator of cap rate, the numerator of debt service coverage ratio, the starting point for unlevered cash flow, and the single number a lender, an appraiser, and a buyer will spend the most time arguing about. The formula is mechanically simple (revenue minus operating expenses) but the institutional conventions around which revenue andwhich expenses make the difference between a number the IC will accept and a number the lender will rebuild from scratch.
For the methodology behind the broker-vs-institutional split (T-12 normalization, market vs. in-place rent, capex reserves above vs. below the line, management fee inclusion, non-recurring stripping), see the companion methodology pillar:Broker NOI vs. Institutional NOI. This page is the widget; that page is the deep dive.
What NOI Measures
NOI measures a property's unlevered, pre-tax operating income: the cash a property would generate annually if it were owned free and clear, before debt service, before depreciation, and before any capital expenditures. It is the cleanest single number for comparing the operating economics of one asset to another, and it is the input that flows into cap rate (NOI ÷ value), debt service coverage ratio (NOI ÷ debt service), and the first year of every multi-year unlevered cash flow.
The formula:
- Effective Gross Income (EGI) = Gross Potential Revenue − Vacancy and Credit Loss + Other Income
- NOI = EGI − Operating Expenses
- NOI Margin = NOI ÷ EGI
Three line items routinely cause disagreements between practitioners and break the comparability of NOI across deals: (1) replacement reserves, which this page holds below the NOI line (deducting them gives cash flow after reserves, not NOI); (2) management fees, which are normalized to market (illustratively 3–4% of EGI for multifamily, 3–5% for retail and office) even when the in-place owner self-manages; (3) one-time items (lease termination fees, settlement payments, storm damage), which are normalized out of a clean NOI but routinely left in by sellers who benefit from the noise.
The deep treatment of these conventions lives in the methodology pillar:Broker NOI vs. Institutional NOI. Read that next if your reason for landing here is a broker number you don't trust.
How to Use This Calculator
The widget computes three layers of output. Each answers a different question.
The primary NOI
The four boxes at the top return EGI, Total OpEx,NOI, and NOI Margin. The default Phoenix inputs return $2,686,500 of EGI, $1,320,000 of OpEx, an NOI of $1,366,500, and a 50.87% NOI margin. NOI margin is the headline metric (everything else is plumbing), but it is meaningful only in context (see asset-class benchmarks below).
The opex-ratio benchmark
Total OpEx ÷ EGI returns the opex ratio. On the default Phoenix inputs the opex ratio prints 49.1%, against an institutional band of 35–45% for stabilized multifamily. A 4–5 point overshoot is meaningful: either the line items contain non-recurring expense the seller did not strip, or the property is sub-stabilized, or the in-place tax line has already been reassessed up at acquisition. The example is deliberately above band. The benchmark band switches with the asset-class selector. Treat the band as a directional signal, not a definitive comp, since submarket and asset-quality variance is substantial.
The Broker NOI vs. Institutional NOI comparison
The bottom panel rebuilds your NOI two ways. The Institutional NCF column applies the institutional adjustments: market management fee if the entered fee is below 3% of EGI, and capex reserves at $350/unit for multifamily or $0.30/SF for other asset classes, with no stripping of non-recurring items. The first column, NOI as entered (broker basis), reflects the conventions a typical broker OM uses to maximize the headline number: management fee left at in-place, no reserves, and optional stripping of "non-recurring" items the seller categorizes loosely (the 5% toggle). A line under the panel shows the institutional NOI before reserves, so the NOI effect and the reserve effect stay separate. The gap between the two columns is the yield delta at your asking price.
On the default inputs the widget prints $1,366,500 as entered and $1,302,905 of institutional cash flow after reserves: a $63,595 gap (4.7% of the entered NOI), or 23 bps at the default $27.3M ask price (5.01% vs. 4.77%). Of that gap, $595 is the management-fee true-up (the $80,000 entered fee is 2.98% of EGI, just under the 3% the widget imputes) and $63,000 is reserves (180 units × $350). Institutional NOI before reserves is $1,365,905. A lender will rebuild this kind of adjustment on its own before sizing debt.
THE 30-SECOND TAKEAWAY
A gap of several percent between the broker number and the institutional number is normal: not a sign of malpractice, just a sign that two different conventions are in play. Resolve the gap explicitly before debating price. The cap rate cannot be debated if the NOI underneath isn't agreed.
NOI Across Asset Classes
"What's a good NOI margin?" The honest answer is it depends on the asset class. The table below shows institutional opex-ratio bands (Total OpEx ÷ EGI) for the major property types. They are illustrative ranges compiled by Apers, not drawn from a single published survey. NOI margin is the complement: 100% − opex ratio.
| Asset Class | Typical OpEx Ratio | NOI Margin | Drivers |
|---|---|---|---|
| Multifamily (stabilized) | 35–45% | 55–65% | Payroll-heavy; insurance and property tax are the lines to stress |
| Industrial (Tier 1 logistics) | 10–20% | 80–90% | Under NNN leases the tenant pays most opex; structural roof/wall items often stay with the landlord |
| Office (Class A, gross lease) | 40–55% | 45–60% | HVAC, janitorial, security; TI/LCs sit below the NOI line |
| Office (Class A, NNN) | 10–15% | 85–90% | Tenant reimburses taxes, insurance, and maintenance; landlord typically keeps vacancy, non-recoverable costs, and often structural items (capex sits below NOI) |
| Anchored Retail (NNN) | 15–30% | 70–85% | CAM recovery rate is the variance; vacancy on small-shop space matters |
| Self-Storage | 25–35% | 65–75% | Low payroll; tenant insurance and ancillary revenue lift margin |
| Hospitality (full-service) | 65–75% | 25–35% | Departmental + undistributed costs; payroll & F&B compress margin |
Illustrative asset-class opex bands, compiled by Apers. The ratio is Total OpEx ÷ EGI; for NNN assets, compare ratios only on the same basis (recoveries in EGI with the matching expenses in OpEx, or net of tenant-paid items).
Two reads from this table that matter for the calculator user. First, NOI margin is not comparable across asset classes: an industrial property at 85% NOI margin and a multifamily property at 60% NOI margin are not better-or-worse, they are differently structured. Industrial NNN pushes most of the opex onto the tenant; the landlord books a tighter, cleaner margin against gross rents that are already net of those items. Multifamily landlords absorb payroll, utilities, marketing, and turnover. The higher opex ratio is structural.
Second, the margin bands move with the cost base. Insurance, property tax, payroll, and utilities reprice over time, so older comp data can read low against current costs. Industrial NNN margins are less exposed because the tenant carries the variable opex. Benchmark against recent comp data from the same submarket where you can.
What NOI Excludes
A clean NOI excludes five categories of cash flow that practitioners regularly confuse for operating expense. Each exclusion has a reason; each reason matters for how you compare NOI to other metrics downstream.
Debt service
NOI is unlevered. Mortgage principal and interest sit below the NOI line. Your actual equity yield depends on leverage, debt cost, and capital reserves, not on NOI alone. The metric that captures debt service is DSCR: NOI divided by annual debt service. See the DSCR calculator for that math.
Depreciation and amortization
Depreciation is an accounting expense, not a cash cost. NOI is a cash-yield metric, so depreciation is excluded. The IRS-recognized depreciation schedules (27.5 years for residential rental property, 39 years for nonresidential real property, per IRC 168(c)) matter for tax modeling, not for NOI.
Capital expenditures (capex) and replacement reserves
Capex (roof replacement, HVAC overhaul, parking-lot resurfacing) sits below NOI.Replacement reserves, the annual accrual that pre-funds known future capex, are also held below NOI on this page. The primary NOI above is before reserves, and the Broker vs. Institutional comparison deducts them separately to show cash flow after reserves.
Tenant improvements and leasing commissions (TI/LCs)
For office, retail, and industrial deals, TI/LCs are real cash outflows that sit below NOI. Tenant improvements and leasing commissions on a single office lease can be large relative to that lease's first-year NOI. The mistake is to compute NOI cleanly and then forget these costs when sizing the equity check.
One-time and non-recurring items
Lease termination fees, settlement payments, insurance recoveries, the year-end utility refund, a one-off storm damage line: all should be normalized out of a clean stabilized NOI. The honest test is whether the item will recur in a normal year. If yes, keep it. If no, strip it, but disclose what you stripped, because the broker might not have.
See the methodology pillar (Broker NOI vs. Institutional NOI) for the conventions around when to strip vs. normalize, the T-12 vs. T-3 question, market vs. in-place rent, and the rest of the institutional NOI rulebook.
Common Mistakes in NOI Calculation
Seven recurring mistakes account for most NOI disputes between buyers, sellers, lenders, and appraisers. Each is straightforward to avoid once named.
Using broker NOI as the underwriting NOI. A higher headline NOI is the broker convention: not malicious, just optimized for headline cap rate. The lender will rebuild it; the buyer should too. The Broker vs. Institutional comparison in the widget above is built to surface the magnitude of the rebuild before you debate price.
Including replacement reserves above the NOI line. This page holds reserves below NOI. Mixing conventions makes the cap rate and DSCR non-comparable to comp data. If the reserves are above the line, either rebuild the NOI or apply the equivalent adjustment to every comp you're using.
Using management fee at the in-house rate when the property is self-managed.Institutional convention is to normalize management fee to market (illustratively 3–4% of EGI for multifamily, 3–5% for retail and office) even when the in-place owner self-manages at a lower rate. The justification: the next buyer may not self-manage, and the cap rate must reflect the third-party operating cost basis.
Treating one-time income as recurring. Lease termination fees, settlement payments, insurance recoveries, the year-end utility refund: all are non-recurring and should be normalized out. Brokers leave them in; buyers strip them; lenders strip them more aggressively. Be explicit about what you stripped and why.
Treating one-time expenses as non-recurring when they aren't. Storm damage in a storm-prone market is not non-recurring; it is an under-reserved insurance event. Coastal Gulf and Florida multifamily storm-damage lines that print zero in T-12 because the property got lucky should be reserved for, not stripped. Honesty cuts both ways.
Pricing on in-place property tax instead of post-acquisition reassessment.Rules differ by state. Florida assesses non-homestead commercial and larger residential property at just value after a change of ownership or control, then caps annual assessed-value changes at 10% for levies other than school district levies (Fla. Stat. 193.1555). Arizona limits annual growth in limited property value to 5% (A.R.S. 42-13301), and that section has no change-of-ownership reset, but confirm the county assessor's treatment before underwriting the Phoenix example. The widget prints a clean NOI on the seller's tax number; where the state reassesses on sale, your underwriting should print a clean NOI on the reassessed number. As a stress, a 20–30% increase on the example's $310,000 tax line is $62,000–$93,000 a year.
Using a T-3 or T-1 instead of a T-12. Short trailing periods miss seasonality: utility costs in summer Texas multifamily, snow removal in winter Midwest office, hospitality occupancy in shoulder months. Use T-12 as the floor; T-24 or T-36 when available, especially for hospitality and seasonal multifamily. The methodology pillar covers the T-12 normalization workflow in detail.
Related Articles
The NOI calculator is the anchor for the Apers Learn valuation cluster. Sibling deep-dives:
- Broker NOI vs. Institutional NOI: The Methodology: the deep treatment of T-12 normalization, market vs. in-place rent, reserves placement, management fee imputation, and one-time stripping. The companion pillar to this calculator.
- Cap Rate Calculator and Formula: NOI is the numerator of cap rate. Once you have a clean NOI, this is the screen.
- DSCR Calculator and Formula: NOI is the numerator of debt service coverage. The lender's view of the same NOI you computed above.
- Cash-on-Cash Calculator and Formula: the levered, after-debt view that takes NOI as its starting point and subtracts debt service to get cash flow to equity.
- IRR Calculator and Formula for Real Estate: the multi-year, time-weighted return that depends on the full NOI projection, not the year-one number.
FAQ
Frequently Asked Questions
What is NOI in commercial real estate?
Net Operating Income (NOI) is a property's annual income after operating expenses but before debt service, depreciation, capital expenditures, and income taxes. It measures the unlevered cash yield of the asset itself, independent of how it is financed. NOI is the numerator of cap rate (NOI ÷ value) and DSCR (NOI ÷ debt service), and the starting point for unlevered cash flow.
How do you calculate NOI?
NOI = Effective Gross Income (EGI) − Operating Expenses. EGI is gross potential revenue, minus vacancy and credit loss, plus other income (parking, laundry, RUBS, ancillary fees). Operating expenses are the nine-line institutional stack: property tax, insurance, repairs and maintenance, property management fee, utilities, payroll, marketing, professional services, and other G&A. Use the calculator above to compute it on your inputs.
What's the difference between NOI and EBITDA?
NOI is a real-estate-specific, property-level metric that excludes depreciation, amortization, debt service, income taxes, capex, and TI/LCs. EBITDA is a corporate-finance metric measured at the operating-company level, before interest, taxes, depreciation, and amortization, and after all of the company's operating expenses, including corporate overhead that property-level NOI does not carry. On a single-asset operating company they can be close, but they are not the same definition.
Does NOI include debt service?
No. NOI is unlevered: it is computed before mortgage interest and principal. Debt service sits below the NOI line. The metric that combines NOI and debt service is the Debt Service Coverage Ratio (DSCR), which is NOI divided by annual debt service.
Does NOI include depreciation?
No. Depreciation is an accounting (non-cash) expense and is excluded from NOI. NOI is a cash-yield metric. Tax depreciation matters for after-tax returns and Schedule E, but it does not enter the NOI calculation.
Does NOI include capital expenditures?
No. Capital expenditures (capex), such as major roof, HVAC, parking lot, and building system replacements, sit below the NOI line. Replacement reserves (the annual accrual that pre-funds expected capex) are also held below the NOI line on this page. Deducting them gives cash flow after reserves, which is how some lenders and underwriters reach underwritten cash flow. The Broker vs. Institutional comparison in the widget above shows NOI as entered next to institutional cash flow after reserves.
Does NOI include reserves?
This calculator holds replacement reserves below the NOI line. Illustrative levels are $300–$400/unit/year for multifamily and $0.20–$0.40/SF/year for office and retail, varying with property age. A figure that deducts reserves is cash flow after reserves, not NOI, and the two differ by the reserve amount, so they are not directly comparable. The comparison panel in the widget deducts reserves separately for that reason.
What is included in operating expenses for NOI?
The institutional operating-expense stack includes nine line items: property tax, insurance, repairs and maintenance, property management fee, utilities, payroll, marketing and advertising, professional services (legal, accounting, audit), and other / general and administrative. Excluded above the NOI line: debt service, depreciation, amortization, capital expenditures, replacement reserves (held below the line on this page), tenant improvements, and leasing commissions.
How is NOI used to calculate cap rate?
Cap rate = NOI ÷ Property Value. A property generating $1,366,500 of NOI and trading at $27,300,000 carries a 5.01% cap rate. NOI is the numerator; the going-in cap rate is computed on year-one stabilized NOI and the acquisition price. See the cap-rate calculator for the full treatment.
What is a good NOI margin?
Asset-class dependent. Illustratively, multifamily stabilized NOI margin runs 55–65% (35–45% opex ratio); industrial NNN is 80–90%; Class A office gross-lease is 45–60%; anchored retail NNN is 70–85%; self-storage is 65–75%; hospitality is 25–35%. The widget above plots your opex ratio against the band for the selected asset class.
What's the difference between broker NOI and institutional NOI?
Broker NOI typically leaves the management fee at the in-place level (often lower than market), omits reserves, and may strip expenses the seller labels non-recurring. Institutional underwriting normalizes the management fee to market, keeps recurring expenses, and deducts reserves to reach cash flow after reserves. In the worked example, a $595 management-fee true-up and $63,000 of reserves move $1,366,500 of NOI as entered to $1,302,905 of cash flow after reserves, a $63,595 gap (4.7%). See the methodology pillar for the full treatment.
Should I use T-3, T-12, or T-24 to compute NOI?
T-12 is the usual floor: twelve months captures full seasonality. T-3 or T-1 misses winter heating, summer cooling, snow removal, and hospitality occupancy swings; do not use as the base. T-24 or T-36 is useful when the property has had ownership or management changes recently or when the T-12 contains visible one-offs. For hospitality and seasonal multifamily, request T-24 or longer when available.
Sources
- 26 U.S.C. 168(c), applicable recovery periods (27.5 years for residential rental property, 39 years for nonresidential real property).govinfo.gov, U.S. Code 2023 Edition, Title 26, Sec. 168
- Fla. Stat. 193.1555, assessment of certain residential and nonresidential real property.leg.state.fl.us
- A.R.S. 42-13301, limited property value (Arizona).azleg.gov/ars/42/13301
- Legal Information Institute, Wex: triple net lease.law.cornell.edu/wex/triple_net_lease