Operating Expense Ratio Calculator
Find operating expenses as a share of revenue.
Results update as you type.
How it works
The operating expense ratio (OER) measures how much of a company's revenue is consumed by the cost of running the business, and this calculator computes it. You enter operating expenses and revenue, and it returns the OER as a percentage. Operating expenses are the ongoing costs of operations — things like salaries, rent, utilities, marketing, insurance, and administration — excluding the cost of goods sold, interest, and taxes. Dividing them by revenue shows what share of each dollar earned goes to keeping the business running, so a lower OER indicates greater efficiency and leaves more revenue for profit. Tracking the OER over time reveals whether costs are growing faster than revenue, a warning sign, or whether the business is gaining operating leverage as it scales. Comparing it to competitors shows relative cost discipline. In real estate investing, the OER is used specifically to evaluate rental properties, dividing operating expenses by gross operating income to gauge how efficiently a property is managed; a lower ratio there means more income is retained. What counts as a good OER depends heavily on the industry, since cost structures vary widely, so it is most useful compared within a sector or against a company's own history. Enter operating expenses and revenue to find the operating expense ratio.
OER = operating expenses ÷ revenue × 100
The operating expense ratio is operating expenses divided by revenue, expressed as a percentage. It shows what portion of each revenue dollar goes to running the business, so a lower ratio means the company keeps more of its revenue and operates more efficiently.
Source:Financial analysis
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Worked example
How to use this calculator
- 1
Enter your values
Enter operating expenses and revenue.
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Operating expense ratio updates instantly as you type — no button to press.
Frequently asked questions
How do you calculate the operating expense ratio?
Divide operating expenses by revenue and multiply by 100. With $35,000 in operating expenses and $100,000 in revenue, the OER is 35 percent. It shows what portion of each revenue dollar is consumed by running the business, so a lower ratio means the company operates more efficiently and retains more for profit.
What counts as operating expenses?
Operating expenses are the ongoing costs of running the business — salaries, rent, utilities, marketing, insurance, office costs, and administration. They typically exclude the cost of goods sold, interest on debt, and taxes, which are accounted for separately. Using a consistent definition of operating expenses is important for meaningful comparisons over time or against competitors.
Is a lower operating expense ratio always better?
Generally a lower OER means greater efficiency and more revenue kept as profit, which is good. But cutting expenses too far can harm quality, growth, or morale, so the goal is efficient spending, not minimal spending. A very low ratio achieved by underinvesting can hurt the business long term, so interpret it alongside growth and quality.
How is OER used in real estate?
For rental properties, the operating expense ratio divides a property's operating expenses by its gross operating income, showing how efficiently the property is run. A lower ratio means more of the income is retained after operating costs. Real estate investors use it, alongside cap rate and cash flow, to compare properties and assess management efficiency.
What is a good operating expense ratio?
It varies widely by industry because cost structures differ, so there is no single benchmark. Service businesses, manufacturers, and retailers have very different typical ratios. The OER is most useful compared within an industry or tracked over time for the same company, where a stable or falling ratio alongside rising revenue signals healthy, efficient operations.