Net operating income is the number a commercial appraisal is built on. Get it wrong by five percent and the value moves by five percent. Owners send us their profit and loss statement expecting it to be used as-is, and it almost never is.
- How to calculate NOI step by step
- Which expenses belong in NOI and which are excluded
- Why an appraiser reconstructs the owner’s numbers before applying a cap rate
What Net Operating Income Actually Measures
Net operating income is the annual income a property produces after operating expenses, but before debt service, income taxes, depreciation, and capital expenditures. It measures the earning power of the real estate itself, separate from how any particular owner financed or structured it.
That separation is the point. Two buyers can pay the same price for the same building with completely different loans. The property still throws off the same income. NOI is what makes properties comparable to one another.
How to Calculate NOI, Step by Step
Start at the top of the rent roll and work down. Here is a simple example for a small multi-tenant building:
- Potential gross income: $1,000,000, the rent if every space were leased at market
- Less vacancy and collection loss at 7 percent: $70,000
- Effective gross income: $930,000
- Less operating expenses: $340,000
- Less replacement reserves: $30,000
- Net operating income: $560,000
Apply a 7 percent capitalization rate to that $560,000 and the indicated value is $8,000,000. Move NOI by $28,000, which is five percent, and the value moves by $400,000. Small errors in the income line become large errors in value.
What Belongs in NOI and What Does Not
Operating expenses are the recurring costs of running the property. Include property taxes, insurance, utilities not reimbursed by tenants, repairs and maintenance, management fees, janitorial and landscaping, and reserves for replacement of short-lived items such as roofs and parking lots.
Leave out mortgage principal and interest, income taxes, depreciation, capital improvements, leasing commissions and tenant improvement allowances, and any expense personal to the owner. A vehicle payment or a family salary that would disappear the day the property sold does not belong in a market-based analysis.
Owners often push back on the management fee. Even an owner who self-manages should show a market management expense, because a buyer would either pay a manager or value their own time. Leaving it out inflates NOI and produces a value the market will not support.
Why Appraisers Rebuild the Owner’s Numbers
An appraisal reflects what a typical buyer would expect, not what one owner happened to experience last year. So the appraiser reconstructs the statement using market rent, market vacancy, and market expense levels, then compares that reconstruction against the property’s actual history and against expense comparables.
Non-market conditions get adjusted too. Federal appraisal guidance addresses this directly. The Interagency Appraisal and Evaluation Guidelines require appraisers to analyze and report appropriate deductions and discounts for partially leased buildings and for leases with terms that do not reflect current market conditions. A building leased to the owner’s brother at half market rent will be analyzed on both the contract and the market basis, and the report will explain which one drives the value.
NOI Is Not Cash Flow, and It Is Not Taxable Income
Three numbers get confused constantly, and they are not interchangeable. NOI stops before debt service. Cash flow before taxes subtracts the mortgage payment from NOI. Taxable income follows a different set of rules again, with depreciation and interest treated the way the tax code says rather than the way an appraiser treats them.
Lenders care about the gap between NOI and debt service, because that gap is the debt service coverage ratio. Appraisers care about NOI because it feeds the income approach. Your CPA cares about the tax figures, and that is properly their work rather than ours. If your accountant and your appraiser show different numbers for the same building, both can be correct, because they are answering different questions.
So before you accept a value conclusion, look at the income reconstruction. If the vacancy assumption, the expense ratio, or the management fee looks off compared to your market, that is the conversation to have with the appraiser.
Your Value Starts With Your Income Line
PahRoo reconstructs income and expenses against real market evidence, then shows the reconstruction so you can see exactly where the value came from.
Frequently Asked Questions
What expenses are included in NOI?
Recurring costs of operating the property, including property taxes, insurance, unreimbursed utilities, repairs and maintenance, management fees, janitorial and landscaping, and reserves for replacement of short-lived building components.
Does NOI include the mortgage?
No. Net operating income is calculated before debt service, so mortgage principal and interest are excluded. This lets properties be compared on the earning power of the real estate rather than on how a particular owner financed it.
How is NOI different from cash flow?
Cash flow before taxes equals NOI minus debt service. NOI stops before the mortgage payment. Taxable income differs again, because depreciation, interest, and capital costs are treated under tax rules rather than appraisal practice.
Why does an appraiser change my operating statement?
Because market value reflects what a typical buyer would expect, not one owner’s actual experience. The appraiser applies market rent, market vacancy, market expenses, and a market management fee, then compares that reconstruction to the property’s history.
Should replacement reserves be deducted from NOI?
In most commercial appraisal practice, yes. Reserves cover the periodic replacement of short-lived items such as roofs, HVAC units, and parking surfaces. The treatment should be consistent with how reserves were handled in the sales used to derive the cap rate.
Check the Income Reconstruction Before You Rely on the Value
PahRoo Appraisal & Consultancy analyzes rent rolls, leases, and operating statements for income-producing property across Chicago and Cook County, Dallas-Fort Worth, Philadelphia, Phoenix, and Naples. We show the reconstruction rather than hiding it in an appendix. Review our commercial appraisal services, request a preliminary consultation, or call 773-388-0003 to talk through a property.
