Definition
Operating expense ratio measures operating expenses as a percentage of revenue.
Formula
Operating expense ratio = operating expenses / revenue
Example
Opex $600k on $2M revenue yields a 30% ratio.
How to use it
- Track by function to see which teams scale with revenue.
- Use trailing periods to smooth volatile months.
Common mistakes
- Comparing ratios without adjusting for revenue recognition timing.
- Treating one-time expenses as recurring operating cost.
Measured as
Operating expense ratio = operating expenses / revenue
Misused when
- Comparing ratios without adjusting for revenue recognition timing.
- Treating one-time expenses as recurring operating cost.
Operator takeaway
- Track by function to see which teams scale with revenue.
- Use trailing periods to smooth volatile months.
- Tie Operating Expense Ratio to the same balance-sheet date, scenario, and decision memo you are using elsewhere in the model.
- Document which claims, costs, or adjustments your team includes before comparing numbers across forecasts, covenants, or valuation work.
Next decision
- Decide whether Operating Expense Ratio belongs in cash planning, valuation, or debt monitoring so the number is used in the right model.
- If the number changes, trace the timing, policy, or balance-sheet assumption behind it before you react.