Operating Expense Ratio

• Debt service, capital improvements, depreciation, and personal expenses are generally excluded from the core operating expense comparison.
• OER should be reviewed with cap rate, net operating income, occupancy, and market benchmarks, not in isolation.

What Is the Operating Expense Ratio and What Does It Tell You?

The Operating Expense Ratio compares the cost of running an income-producing property to the revenue that property generates. In plain terms, it answers: how much of each dollar of property income is being spent just to keep the property operating?

Property owners and investors watch OER because it can reveal whether a building is being managed efficiently. A rising OER may point to higher maintenance, utilities, insurance, taxes, vacancies, or property management cost. A lower OER usually means more income remains after recurring expenses, which can support stronger real estate cash flow and valuation.

OER is especially useful over time. One year may reflect a repair spike. Three to five years can show a pattern.

How to Calculate OER With a Real Example

The common formula is:

Operating Expense Ratio = Operating Expenses ÷ Gross Operating Income

Some calculations subtract depreciation from operating expenses, because depreciation is a non-cash accounting expense rather than a day-to-day operating cost. The supplied source example uses operating expenses less depreciation divided by gross revenue.

Assume a rental property generates $900,000 in annual gross operating income and has $405,000 in annual operating expenses.

$405,000 ÷ $900,000 = 45%

That means 45 cents of each revenue dollar goes toward operating the property.

Typical operating expenses include repairs, maintenance, insurance, property taxes, utilities, trash removal, landscaping, leasing costs, management fees, and similar recurring rental property expenses. Items generally excluded include mortgage payments, income taxes, capital improvements, depreciation in many practical analyses, and owner-specific costs. Certain professional costs may appear depending on the context, but legal and transaction fees in real estate should be reviewed carefully because acquisition, financing, or sale-related costs are not the same as routine property operations.

What a Healthy OER Looks Like Across Property Types

There is no universal “good” OER. Property type matters. Multifamily properties are often benchmarked around the mid-30% to mid-40% range in some sources, while broader rental property data may show higher ranges depending on size, utilities, payroll, taxes, and age. Office properties often run higher because they can require more services, maintenance, utilities, and common-area support. Retail varies widely based on lease structure. Industrial and warehouse properties often show lower OERs because they typically have simpler operating requirements.

A “healthy” OER is one that fits the asset, market, lease terms, and strategy. For example, a 60% OER may be alarming for a warehouse but expected for a service-heavy property with owner-paid expenses. The practical use is comparison: compare the property to similar properties, then investigate outliers. If utilities, repairs, vacancies, insurance, or taxes are moving faster than income, OER is waving the little yellow flag before the big red one arrives.

What OER Tells You That Cap Rate Cannot

Cap rate estimates return by comparing net operating income to property value. OER focuses on operating efficiency. Cap rate asks, “What return does this property appear to produce at this value?” OER asks, “Is the property being run well enough to preserve income?”

That distinction matters. Two properties can have similar cap rates, but very different expense profiles. OER can help identify whether management fees are too high, maintenance is reactive instead of planned, vacancies are eroding income, utilities are out of line, or rents have not kept pace with costs. Cap rate is a valuation lens. OER is an operating lens.

FAQ

Does OER change significantly as a building gets older or less maintained?
 Yes. Older or under-maintained buildings often require more repairs, replacements, utilities, insurance, and hands-on management. OER may rise if expenses increase faster than income. A rising ratio is not automatically bad, but it should trigger a closer review.

Can a high OER ever be acceptable depending on the property or strategy?
 Yes. A high OER may be acceptable for a value-add property, heavy-service asset, older building, or property with owner-paid utilities. The key question is whether the ratio reflects a deliberate strategy, temporary condition, or an operating problem.

How does owning a triple net lease property change the OER calculation?
 In a triple net lease, tenants often pay taxes, insurance, maintenance, and other property costs directly or through reimbursements. That can make the owner’s OER look unusually low, so investors should review lease terms before comparing it to other properties.

How is OER different from the expense ratio used when evaluating stocks or funds?
 In real estate, OER measures property operating costs against property income. In stocks or funds, an expense ratio usually measures management and administrative fees charged to investors.

How BT Can Help

For more than four decades, Bennett Thrasher has provided businesses and individuals with strategic business guidance and solutions through professional tax, audit, advisory, and business process outsourcing services. Contact Trey Webb, partner in charge of Bennett Thrasher’s Real Estate and Hospitality Tax Group, or call us at 770.396.2200.