What is the NOI formula in real estate?

NOI = Gross Revenue − Operating Expenses. For commercial real estate, gross revenue includes base rent, CAM recoveries, tax recoveries, insurance recoveries, percentage rent, and other income. Operating expenses include property management fees, maintenance, utilities, insurance, property taxes, and landscaping — before debt service, depreciation, and income taxes. The formula looks simple but the complexity is in correctly accounting for both sides of the recovery equation: CAM expenses appear on the expense side and CAM recovery revenue appears on the revenue side. Underbilling creates an asymmetry where expenses are incurred without full offsetting revenue.

How do I calculate net operating income step by step?

Step 1: Add all base rent from active leases. Step 2: Calculate recovery revenue — CAM billed × recovery ratio, plus property tax and insurance recoveries. Step 3: Add percentage rent and other income. This is your Effective Gross Income (EGI). Step 4: Subtract operating expenses: management fees, CAM costs incurred, taxes, insurance, maintenance. Step 5: NOI = EGI − Total Operating Expenses. The critical step most operators get wrong is Step 2 — they record estimated recoveries rather than reconciling actuals. If CAM billed is $50,000 but actuals were $62,000 and you didn't send a true-up, your EGI is overstated by $12,000 in estimates and understated by $12,000 in real revenue simultaneously.

Does CAM recovery increase NOI?

CAM recovery revenue increases the revenue side of NOI, while CAM expenses increase the cost side. When recovery is perfect (100%), they net to zero impact — the property is simply passing costs through to tenants with no landlord exposure. When recovery is below 100%, the un-recovered portion is a net NOI cost equal to CAM expense × (1 − recovery rate). So on $600,000 in CAM expenses at 87% recovery, the landlord absorbs $78,000 (13% × $600,000) as a direct NOI reduction. Improving recovery doesn't create new income — it recaptures revenue you're contractually entitled to but failing to bill.

What's the difference between NOI and EBITDA for real estate?

NOI is property-specific and excludes debt service, taxes, depreciation, and capital costs. EBITDA (Earnings Before Interest, Taxes, Depreciation, and Amortization) is a company-level metric that adds back depreciation and amortization to operating income. For a REIT or property company, EBITDA includes corporate overhead, management company income, and other non-property items. NOI is cleaner for single-asset analysis because it focuses purely on operating performance. Lenders and appraisers use NOI; equity analysts often use EBITDA or FFO (Funds From Operations) for publicly traded REITs.

How does occupancy affect the NOI formula?

Occupancy affects NOI in two ways. First, vacant space generates no base rent — straightforward revenue reduction. Second, it affects the recovery ratio because CAM expenses for vacant space often can't be fully recovered unless the lease allows gross-up. A property dropping from 95% to 85% occupancy loses 10 percentage points of rent but may lose 10-15 percentage points of recovery ratio (depending on gross-up provisions). For modeling, always calculate NOI at both current occupancy and stabilized occupancy. The difference shows lease-up value and helps you benchmark whether CAM gross-up provisions are working as intended. The CAM gross-up calculator at /tools/cam-gross-up-calculator handles this math automatically.

NOI Formula: Complete Calculation Guide with CAM Recovery Examples

By Angel Campa·Founder, CapVeriUpdated April 24, 2026

NOI Formula

NOI = Gross Revenue − Operating Expenses. For CRE, the critical detail is that CAM recovery revenue must appear on the revenue side while CAM expenses appear on the cost side. When they're equal, CAM is pass-through. When recovery is less than expenses incurred, the gap reduces NOI dollar-for-dollar.

The NOI formula has four words: revenue minus operating expenses. The work is in getting both sides right — particularly the recovery revenue that most operators consistently underbill by 5-15%.

The NOI Formula

NOI = Gross Revenue − Operating Expenses

Where:
Gross Revenue = Base Rent + CAM Recovery + Tax Recovery
              + Insurance Recovery + Percentage Rent + Other Income

Operating Expenses = CAM Costs Incurred + Property Taxes
                   + Insurance + Management Fees + Maintenance
                   + Utilities (landlord) + Admin

Note what's excluded from Operating Expenses: debt service, depreciation, income taxes, capital expenditures, leasing commissions, TI allowances. These are below-the-line items that NOI deliberately ignores so the metric reflects operational performance independent of financing structure.

Step-by-Step NOI Calculation

Property Setup: 120,000 sf suburban retail center, 92% occupied (110,400 sf leased), Denver market.

Step 1: Calculate Base Rent

Sum all active leases using scheduled rent, not market rent:

Tenant Type	Leased SF	Rent/sf/yr	Annual Amount
Anchor (big box)	45,000	$12.50	$562,500
Co-anchors (2)	24,000	$18.00	$432,000
Junior box	12,000	$22.00	$264,000
Inline tenants (18)	29,400	$32.00	$940,800
Subtotal	110,400		$2,199,300

Step 2: Calculate Recovery Revenue

CAM Recovery:

Total CAM expenses incurred for the year: $744,000 (across 120,000 sf of total GLA)

Billable CAM = total pool × weighted recovery ratio by tenant group:

Anchor: excludes management fees and admin → effective rate 78%
Co-anchors: standard 95% with 5% admin cap
Junior box: 90% with 3% annual cap
Inline: 95% standard, no cap

Blended recovery by sf-weighted average: 87.2%

CAM Recovery Revenue: $744,000 × 87.2% = $648,768

Tax Recovery: Property tax bill $392,000, all leases 100% recoverable → $392,000

Insurance Recovery: $58,000 premium, 100% recoverable → $58,000

Step 3: Add Percentage Rent and Other Income

Percentage rent (anchor tenant, >$8M in sales): $28,000
Antenna lease (cell tower on roof): $36,000
Parking deck surplus: $0 (included in CAM)

Other income: $64,000

Step 4: Effective Gross Income

Revenue Component	Amount
Base Rent	$2,199,300
CAM Recovery	$648,768
Tax Recovery	$392,000
Insurance Recovery	$58,000
Other Income	$64,000
Effective Gross Income	$3,362,068

Step 5: Operating Expenses

Expense Category	Amount
CAM Expenses (incurred)	$744,000
Property Taxes	$392,000
Insurance	$58,000
Management Fee (4%)	$134,483
Non-Recoverable Maintenance	$28,000
Legal/Accounting/Admin	$42,000
Total Operating Expenses	$1,398,483

Step 6: Net Operating Income

NOI = $3,362,068 − $1,398,483 = $1,963,585

At a 6.75% cap rate: Implied Value = $29.1 million

The Hidden Number: True NOI with Full Recovery

What if the 87.2% blended recovery rate improved to 95%?

Additional CAM recovery: $744,000 × (95% − 87.2%) = $744,000 × 7.8% = $58,032

True NOI at 95% recovery: $1,963,585 + $58,032 = $2,021,617

Implied value at 95% recovery and 6.75% cap: $29.95 million

Value gap from under-recovery: $860,000 — from billing methodology, not operations.

This is the calculation the net-operating-income-real-estate-guide explores in full context. The noi-calculation-example resource shows three additional property scenarios side by side.

Adding Back Under-Recovered CAM to Get True NOI

Most financial reporting shows NOI as-billed. For internal management and pre-sale diligence, you need to also know theoretical NOI — what NOI would be if every recoverable dollar were actually billed and collected.

True NOI Formula:

True NOI = Reported NOI + Unrecovered CAM (within lease rights)

Unrecovered CAM = Total CAM Pool × (Max Theoretical Recovery % − Actual Recovery %)

Where Max Theoretical Recovery % is the recovery rate if every tenant paid their pro-rata share up to their lease maximum (before caps bind).

To calculate the max theoretical rate, you need a lease-by-lease analysis:

Pull each tenant's pro-rata share (their sf ÷ total GLA or denominator per lease)
Identify whether the lease has a CAM cap and whether it's binding this year
Calculate the theoretical billing for each tenant: min(pro-rata × pool, cap)
Sum across all tenants → theoretical maximum recovery
Divide by total CAM pool → max theoretical recovery %

For the 120,000 sf example above: if caps aren't binding on any tenant this year, max theoretical recovery might be 95.5% (the 4.5% gap is from the anchor's exclusions). If you're achieving 87.2%, the gap is 8.3 percentage points — most of which is billing error or missing reconciliation, not lease structure.

Use the cam-gross-up-calculator and pro-rata-calculator to automate this analysis across your portfolio.

Common NOI Calculation Errors

Error 1: Using Estimated Instead of Actual Recovery

Many operators recognize estimated recovery revenue monthly and never reconcile. The cam-true-up process exists precisely because estimates drift from actuals. If you're running a 5% overestimate for 8 months, your YTD NOI is overstated — and you may owe tenants refunds, making actual NOI even lower than corrected estimates.

Error 2: Double-Counting Management Fees

Management fees appear in operating expenses (as a cost). If your leases exclude management fees from the CAM pool, they also shouldn't appear in the CAM recovery revenue calculation. Including management fees in CAM when the lease excludes them is an overbilling error — see cam-overbilling-liability.

Error 3: Excluding Gross-Up Adjustment

For properties under 90% occupancy, the gross-up adjustment can materially change both the expense pool (for billing purposes) and the recovery revenue. Failing to apply a permitted gross-up means you're under-billing — and understating NOI. The methodology is in the cam-gross-up-calculation-guide.

Error 4: Treating Capital Items as Recoverable Operating Expense

Roof replacement, HVAC systems, parking lot repaving — these are typically capital expenditures, not recoverable operating expenses. Including them in CAM pools inflates your apparent recovery revenue but creates overbilling liability that can come back as tenant credits or disputes. Keep your CAM pool clean to keep your NOI defensible.

Error 5: Missing Pro-Rata Denominator Changes

When tenants expand, contract, or leave, the pro-rata denominator changes. If a 10,000 sf tenant vacates and you don't update denominators, remaining tenants are being billed a higher share than their lease allows. That's overbilling, not legitimate recovery revenue. The pro-rata-share-calculation guide covers denominator management.

NOI Formula for Different Lease Types

Triple-Net (NNN) Property

For a true NNN property: NOI ≈ Base Rent + Percentage Rent + Other Non-Expense Income

Tenants pay expenses directly, so those costs don't flow through your books. But verify the leases are truly NNN — many "NNN" leases have expense stops, gross-up provisions, or administrative fee structures that create partial landlord exposure.

Modified Gross / Industrial Gross

Landlord pays some expenses (often utilities or structural maintenance), tenants pay base rent plus a fixed or capped additional. NOI calculation adds any fixed recovery contributions but excludes variable pass-throughs the tenant pays directly.

Gross Lease Office

Landlord absorbs all operating costs. NOI = Base Rent − All Operating Expenses. Recovery revenue is zero. This structure makes NOI most sensitive to expense control.

Linking NOI to Property Valuation

The noi-to-value-commercial-property resource covers the full valuation mechanics, but the core relationship:

Value = NOI ÷ Cap Rate

NOI	Cap Rate	Value
$1,963,585	6.75%	$29,090,889
$2,021,617	6.75%	$29,950,622
$1,963,585	7.25%	$27,083,931
$2,021,617	7.25%	$27,884,372

Two variables drive value: NOI and cap rate. You can't control cap rates (market-driven). You can control NOI — especially the recovery side. The cap-rate-noi-relationship-cre blog post shows how a 50 basis point cap rate move and a 3% recovery improvement can interact to create very different outcomes.

Occupancy-Normalized NOI

For properties in lease-up or with significant vacancy, stabilized NOI is more useful for valuation than as-is NOI. Calculate it by:

Projecting base rent at target occupancy (typically market occupancy for the submarket, often 93-95%)
Applying full recovery rates at that occupancy (gross-up provisions normalize this)
Using stabilized expense levels (some expenses scale with occupancy, some don't)

The how-to-calculate-noi-real-estate guide covers occupancy normalization in detail, including how to handle free rent periods and absorption assumptions.

Modeling CAM Variance Impact on NOI

Year-end CAM variances — the difference between estimated and actual CAM — directly affect NOI recognition. If your estimates ran $3.50/sf and actuals came in at $4.10/sf, you have a $0.60/sf true-up to bill tenants. Until those invoices are out and collected, your reported NOI overstates the revenue side.

Use the cam-variance-analysis framework to track this gap monthly, not just at year-end. A 15% variance in Q3 is actionable — you can adjust Q4 estimates, communicate with tenants proactively, and avoid the December surprise that makes annual NOI unreliable.

Next Steps

The NOI formula is only as good as the data going into it. If your recovery ratios are estimates or your CAM pools include excluded items, your NOI number is wrong by a calculable amount.

For a complete walkthrough with three different property types side by side, see noi-calculation-example. For the valuation mechanics that turn NOI into property value, see noi-to-value-commercial-property. And if you want to see where your portfolio's recovery gaps are in real-time, the NOI impact calculator quantifies the value at stake from each percentage point of recovery improvement.