NOI Calculation: What Counts, What Doesn't, and Why Lenders Strip Out the Difference
The 6 line items lenders strip out of broker NOI, and the 3 reserves they add back in.
The Textbook NOI Formula vs Reality
Net Operating Income is gross rental income, plus other income (laundry, parking, late fees, pet rent), minus vacancy and credit loss, minus operating expenses. Operating expenses include property taxes, insurance, utilities, repairs and maintenance, payroll, management, marketing, professional fees, and any other recurring cost necessary to operate the asset. The textbook formula stops there.
The number on the offering memo is rarely the textbook number. Brokers and sellers have legitimate incentive to present NOI on a "stabilized" or "pro forma" basis that assumes higher occupancy, lower expenses, or both. The number a lender uses is yet a third version: trailing twelve months adjusted to underwriting standards. The three numbers can easily differ by 15–20%.
The takeaway: there is no single "NOI" — there is broker NOI, operator NOI, and underwritten NOI, and you need to know which one you're looking at.
The Six Line Items Lenders Strip Out
First, non-recurring income: one-time settlements, lease-termination fees, COVID-era rent relief, insurance proceeds. None of it counts. Second, related-party rent: if a tenant is the seller's own business or a controlled affiliate, lenders mark it to market — sometimes flagging the entire revenue line as unreliable. Third, below-market reserves: if the seller is reserving $80/unit/year for capex on a 1980s-vintage apartment building, the lender re-reserves at $300+/unit/year and that delta hits NOI.
Fourth, capex booked as expense: minor capex (interior paint, appliance replacement) that ought to be reserved is sometimes expensed in the trailing-12. Lenders normalize. Fifth, owner-managed addbacks: if there's no management fee on the P&L, the lender adds 4–5% of effective gross income whether you self-manage or not. Sixth, utility cost games: where the seller has shifted utility billing to residents in the past 12 months, the lender de-bumps the income or adds back the expense.
Cumulatively, the six adjustments routinely strip 8–15% out of broker NOI. On a $500K NOI deal, that's $40K–$75K — enough to move DSCR by 0.10x and shift you out of agency eligibility.
The Three Reserves Lenders Add Back
Lenders impose three standard reserves regardless of what the seller has on their P&L. First, replacement reserves: $250–$300 per unit per year for stabilized multifamily in good condition; $400+ for 1970s-and-older product. Self-storage runs $0.10–$0.15 per square foot; commercial offices run $0.20–$0.30 per square foot per year.
Second, structural reserves on properties with deferred maintenance: roof, HVAC, parking lot, elevator. The property condition report (PCR) drives these — every item flagged as needing replacement within 5 years gets reserved at the projected replacement cost ÷ remaining useful life. A roof flagged with 4 years remaining at $80K replacement cost adds $20K/year to expenses.
Third, the management-fee reserve mentioned earlier: 4–5% multifamily, 5–7% hospitality, 3–4% commercial single-tenant net leases. Together these three reserves typically add another 5–8% to expenses beyond what the seller shows.
A Worked Example: Broker NOI vs Underwritten NOI
Take a 32-unit garden apartment property. Broker says NOI is $385,000 on $720,000 of rental income — a 53% expense ratio that already feels light. Trailing-12 actual operating expenses are $280,000 plus a $25,000 "one-time legal settlement" that the seller has running through other income. Real operating expenses are $305K, real other income is gross-of-settlement.
Lender adjustments: vacancy floor lifts vacancy from the trailing 4% to 5% ($7,200 hit). Strip the legal settlement ($25,000 hit). Add a 4.5% management fee ($32,400 hit). Add $300/unit replacement reserves ($9,600 hit). Net effect: NOI moves from $385K to $311K — a 19% reduction. DSCR at $1.8M loan / $140K debt service moves from 2.75x (broker) to 2.22x (underwritten). Both pencil — but at different leverage and rate.
On a tighter deal, the same adjustments push DSCR from 1.45x to 1.17x and the deal stops fitting agency. Knowing which number lender will use, before you sign the LOI, is the difference between a deal that closes and a deal that re-trades.
See Broker NOI vs Underwritten NOI On Your Deal →
We apply the six standard lender adjustments to your trailing-12 — vacancy floor, management fee, replacement reserves, related-party rent, non-recurring strip, capex normalization — and show the underwritten NOI that actually drives every quote.
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