Submit a loan package on an income-producing property without understanding net operating income, and you’ll get a surprise on the term sheet — or miss the deal entirely. NOI is the single most important number in commercial real estate underwriting. It drives your loan amount, your interest rate tier, and whether the lender says yes. Here’s what it is, how to calculate it correctly, and how lenders actually use it.
What you’ll learn:
- The NOI formula and how each component is calculated
- What’s included in operating expenses — and what’s explicitly excluded
- The T-12 vs. proforma distinction that changes every underwrite
- How lenders derive DSCR and property value from NOI
- Practical steps to improve NOI before you apply
What Is Net Operating Income?
Net operating income is the income a property generates from operations after subtracting operating expenses, before accounting for debt service or capital expenditures. It measures what the property produces on its own — independent of how it’s financed.
Lenders use NOI for two purposes: to determine the maximum loan amount via the debt service coverage ratio, and to value the property itself via cap rate conversion. Get NOI wrong and both outputs break. That’s why underwriters review it line by line rather than taking the borrower’s stated number at face value.
The NOI Formula, Step by Step
The calculation runs through three layers:
Step 1 — Potential Gross Income (PGI): Total scheduled rent at 100% occupancy and market rates, plus ancillary income: parking, laundry, storage, RUBS (ratio utility billing), and any other recurring revenue the property generates.
Step 2 — Effective Gross Income (EGI): PGI minus vacancy and credit loss. Lenders typically apply a 5–10% vacancy factor on stabilized properties regardless of current occupancy. A property collecting $240,000/year in scheduled rent with a 7% vacancy assumption carries an EGI of $223,200 — even if it’s currently full.
Step 3 — Net Operating Income: EGI minus operating expenses.
The formula: NOI = (PGI − Vacancy & Credit Loss + Other Income) − Operating Expenses
The vacancy haircut trips borrowers up constantly. A property that’s been 100% occupied for three years still gets a vacancy adjustment in the lender’s model, because the loan has to survive a lease-up cycle.
What’s Included in Operating Expenses
Operating expenses are the recurring costs of keeping the property functional and income-producing. Lenders examine each line:
- Property taxes
- Insurance (property, liability, and often flood or windstorm depending on location)
- Repairs and maintenance
- Property management fee (typically 4–10% of effective gross income — lenders impute this even if you self-manage)
- Utilities (for landlord-paid units or common areas)
- Payroll (on-site staff for larger properties)
- Professional services (accounting, legal)
- Reserves for replacement (increasingly required in agency and CMBS underwriting)
The management fee is a recurring sticking point. If you manage your 10-unit building yourself, you may have no management line in your actuals. The lender adds one anyway — typically 8–10% for small multifamily — because they need to know the property can service debt without your free labor. I’ve seen this single adjustment reduce a borrower’s underwritten NOI by $15,000 or more on a mid-size deal.
What NOI Doesn’t Include
This is where inflated NOI figures come from. Common mistakes:
- Debt service — mortgage principal and interest are not operating expenses
- Capital expenditures — roof replacement, HVAC systems, major unit renovations, parking lot resurfacing
- Income taxes — attributable to the investor, not the property’s operations
- Depreciation
If you subtract debt service when calculating NOI, you’re calculating net cash flow — a different and lower number. A lender who asks for NOI and receives net cash flow will notice immediately. It signals the financial package wasn’t prepared correctly, which creates friction before the underwrite even starts.
JP Morgan’s commercial lending team puts it plainly: NOI shows what a property generates from operations before financing costs or large capital events — which is exactly the number a lender needs to evaluate creditworthiness independent of deal structure.
T-12 vs. Proforma NOI: What Lenders Actually Use
This is the most misunderstood part of NOI in a lending context. Borrowers often present proforma NOI — what the property will produce after renovations, lease-up, or rent increases. Lenders underwrite T-12 NOI — what the property actually produced over the trailing 12 months.
Freddie Mac’s underwriting guidance is explicit on this: appraisers and lenders must ensure income and expense data are calculated consistently, with trailing 12-month actuals as the foundation for stabilized property underwriting. Proforma income gets credit only when supported by executed leases, verifiable rent rolls, or documented market rent comparables — not projections.
For value-add deals with vacant units or below-market rents, most lenders blend T-12 actuals with market rent projections and apply a haircut. Bridge lenders are more likely to underwrite to stabilized proforma, but they price that risk into the rate and structure.
My advice: present both T-12 and proforma NOI clearly labeled in your package. Trying to lead with proforma numbers and bury the actuals rarely works — underwriters find everything, and it creates trust issues that can kill a deal even when the underlying numbers are fine.
How Lenders Use NOI: DSCR and Property Value
Debt Service Coverage Ratio
The primary use: DSCR = NOI ÷ Annual Debt Service
Most commercial lenders in 2026 require a minimum DSCR of 1.20–1.25x on stabilized properties. That means the property must generate at least $1.20 in NOI for every $1.00 of annual loan payments. For a property with $150,000 in annual NOI and a lender requiring 1.25x, the maximum supportable annual debt service is $120,000 — and that debt service determines the maximum loan amount at the proposed rate and amortization.
If your NOI is tight, the lender reduces the loan, not the DSCR requirement. See our detailed breakdown of how lenders calculate DSCR on commercial loans for the full mechanics, including how the qualifying rate is set.
Property Valuation
The second use: Value = NOI ÷ Cap Rate
A property generating $150,000 NOI in a market where comparable properties trade at a 6.5% cap rate appraises at roughly $2.3 million. Lenders don’t just accept the appraiser’s cap rate — they develop their own view based on comparable sales, lease term, property condition, and market dynamics.
This is why cap rate selection matters as much as NOI in commercial underwriting. A 50-basis-point cap rate adjustment on that same $150,000 NOI swings appraised value by over $175,000. Both inputs get challenged.
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From a Recent Deal
From a recent deal: I worked a refinance on a 12-unit apartment building in the Atlanta metro where the borrower had solid occupancy history and was targeting a $1.4M loan. His proforma showed $128,000 in annual NOI. When I ran the T-12 actuals, two units had been vacant for three months during a cosmetic renovation, and he’d been self-managing — no management fee in the expense history. The lender’s underwritten NOI came in at $108,000 after applying the vacancy adjustment and imputing an 8% management fee. At 1.25x DSCR, that changed the maximum supportable loan to roughly $1.1M — a $300,000 gap. We placed the deal with a bridge lender comfortable with the light value-add story, 24-month term, with a clear path to permanent financing once the two units were stabilized and a management agreement was in place.
How to Improve Your NOI Before You Apply
If your NOI is constraining the loan amount, there are real levers:
- Push rents to market. If you’re 10–15% below current market on existing leases, document the gap with recent rental comparables. Some lenders give partial credit toward market rent on a written proforma with supporting comps.
- Add ancillary income. Storage units, coin laundry, covered parking — even modest amounts flow directly to EGI.
- Formalize management. A property management agreement lets the lender use a lower imputed fee (4–6% for a formal PM) rather than their default worst-case assumption.
- Document actual expenses accurately. If your real insurance or tax bill is below the lender’s model, bring the evidence — tax bills, insurance declarations, maintenance invoices. Lenders work from actuals when you provide them.
The goal is not to inflate NOI but to make sure the lender’s model reflects what’s real rather than worst-case assumptions. Given current commercial real estate rates in 2026, every basis point of loan size matters when you’re sizing against a DSCR floor.
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Frequently Asked Questions
What is a good NOI for a commercial property?
“Good” is relative to the purchase price and market cap rate. A property generating $200,000 in NOI isn’t necessarily a better deal than one at $120,000 — it depends on what you paid. For lending purposes, what matters is whether the NOI supports a 1.20–1.25x DSCR on the proposed loan amount at current rates.
Does NOI include mortgage payments?
No. NOI is calculated before debt service. Mortgage principal and interest are excluded because NOI measures the property’s operating performance independent of financing. Subtracting debt service from NOI gives you net cash flow — the investor’s return metric, not the lender’s underwriting metric.
How do lenders verify NOI?
Lenders typically require two years of operating statements, a current rent roll, recent tax returns, and lease abstracts for commercial tenants. They also order a third-party appraisal that independently reconstructs NOI using market comparable data. The appraisal’s NOI often differs from the borrower’s — reconciling that gap is part of the underwriting process.
Can I use proforma NOI to qualify for a commercial loan?
Rarely for permanent financing. Most CMBS, life company, bank, and agency lenders require T-12 actuals as the foundation, with proforma credit only for executed leases or documented market rent adjustments. Bridge lenders may underwrite to stabilized proforma but price the risk accordingly.
Why do lenders impute a management fee if I self-manage?
Because the loan has to work without you. If you sell the property or stop managing it, a third-party manager needs to be hired. Lenders underwrite the property as if it’s professionally managed — the realistic worst-case scenario for the collateral.
This article is for informational purposes only and does not constitute financial, legal, or tax advice. Loan terms, rates, and availability vary by borrower, property, and market conditions. Consult Willowbrook Capital for scenario-specific guidance.
