Operating Expense Ratio for a Small Commercial Property
Calculate the OER for a small commercial building with $60,000 in expenses and $150,000 gross operating income.
How to use this tool
- Enter annual operating expenses (excluding mortgage, capex, and income tax).
- Enter annual gross operating income (effective rent plus other income).
- Read the operating expense ratio.
- Check the resulting NOI and NOI margin.
- Benchmark the OER against comparable properties — 35-45% is typical for residential.
Commercial properties typically target an OER below 45%, and this example with $60K expenses on $150K income lands at 40%.
Frequently asked questions
- What is a good operating expense ratio?
- For residential rentals, an OER in the 35-45% range is common. Lower can mean a more efficient property — or that expenses such as management and reserves have been understated. Compare against similar properties.
- What is excluded from the OER?
- The mortgage payment, income taxes, depreciation, and capital expenditures are all excluded, matching the definition of net operating income. Only recurring operating costs belong in the numerator.
- How does OER relate to NOI margin?
- They are complements: OER + NOI margin = 100%. A 40% OER implies a 60% NOI margin. Tracking one automatically tells you the other.