Landlord Expense Ratio Calculator

The operating expense ratio (OER) is the ratio of a property's total operating expenses to its gross rental income, expressed as a percentage. OER = Total Operating Expenses / Gross Rental Income x 100. A 40% OER means 40 cents of every dollar of gross rent goes to operating costs before debt service.

For residential rental properties in the United States, an OER of 35 to 45% is commonly considered healthy. Multifamily properties often run 40 to 50%. Commercial properties vary widely. A lower OER means more of the gross rent flows to NOI (and ultimately cash flow). Compare to local market data for the most meaningful benchmark.

OER includes all operating expenses: property management fees, property taxes, insurance, maintenance and repairs, utilities paid by the owner, advertising, accounting, and legal fees. It does NOT include mortgage payments (principal and interest), income taxes, depreciation, or capital improvements. These are financing and accounting items, not operating expenses.

The 50% rule is a rough heuristic that says operating expenses on a rental property will total approximately 50% of gross rent. If your analysis shows a much lower OER, double-check that you have included all expenses and a maintenance reserve. The 50% rule includes vacancy, while OER is sometimes calculated on effective gross income.

A lower OER means more NOI for a given level of gross rent, which supports a higher property value under the income capitalization approach (Value = NOI / Cap Rate). Investors and appraisers use OER comparisons to identify properties with unusually high expenses (potential management issues) or unusually low expenses (potential understated costs).