Operating expense ratio calculator.
OpEx as a % of revenue, with sector benchmarks. The first number to check when 'we have customers but no money left.'
Monthly
Defaults assume an average small café.
Operating expense ratio
OpEx ratio is the "can I keep the lights on" number.
Operating expense ratio is the % of revenue eaten by the costs of running the business — rent, payroll, utilities, software, marketing — but NOT the cost of the products themselves. Combined with gross margin, it tells you whether the business model works.
The formula
OpEx ratio = operating expenses ÷ revenue
Healthy ranges by sector
Café / restaurant: 25-35% (combined with 30-35% food cost = 60-70% prime cost). Retail: 25-40% (combined with 50-60% gross margin). Salon: 30-45%. E-commerce: 25-40% (excluding ad spend — include if you treat it as fixed).
What to do if you're above the range
Two levers, both painful but real: cut the biggest line item by 10% (usually rent renegotiation or staff hours), or grow revenue without proportional cost growth (raise prices, increase average ticket, sell to existing customers). Most owners try lever 3 — "cut everything by a little" — which never works because the small lines aren't where the money is.