NodusTechBusiness Expense Ratio Calculator
Enter revenue, cost of goods sold and operating expenses to see your gross margin, operating expense ratio and net operating margin.
How to read your result
Gross marginshows what's left after the direct cost of what you sold. Operating expense ratio shows how much of every euro of revenue gets consumed by running costs like rent, salaries and marketing.
Net operating margincombines both — it's what's left after cost of goods sold and operating expenses, before tax and interest. A shrinking net operating margin over time, even with rising revenue, is an early sign that costs are growing faster than sales.
Worked example
A business has €50,000 revenue, €20,000 cost of goods sold and €18,000 operating expenses. Gross profit = €50,000 − €20,000 = €30,000 (60% gross margin). Operating expense ratio = €18,000 ÷ €50,000 = 36%. Net operating profit = €50,000 − €20,000 − €18,000 = €12,000, a 24% net operating margin.
Formula
Gross margin % = (Revenue − COGS) ÷ Revenue × 100
Operating expense ratio % = Operating expenses ÷ Revenue × 100
Net operating margin % = (Revenue − COGS − Operating expenses) ÷ Revenue × 100
Good to know
These ratios are most useful compared against your own history, not a single universal benchmark — track them monthly or quarterly and watch the direction of travel. A rising expense ratio alongside flat revenue usually means it's time to review specific cost categories rather than cutting broadly.
Frequently Asked Questions
What's the difference between cost of goods sold and operating expenses?+
Cost of goods sold (COGS) is the direct cost of what you sold — materials, stock, direct labour. Operating expenses are the costs of running the business regardless of sales volume — rent, salaries, marketing, software.
What's a "good" operating expense ratio?+
It varies enormously by industry — a service business with low COGS but high staff costs looks very different from a retailer. The number is most useful tracked over time in your own business, watching for it creeping upward.
Can the operating expense ratio be over 100%?+
Yes — that means operating expenses alone exceed revenue, before even accounting for cost of goods sold. It's a clear signal to review costs or pricing.
Does this include tax, interest or depreciation?+
No. This calculator stops at net operating profit — profit before interest, tax, depreciation and amortisation. That keeps it focused on operating performance rather than financing or accounting choices.
Need category, supplier and budget-level cost control, not just one ratio?
Business Expense Tracker & Cost Control Suite — €19.99
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This calculator is provided for general information only and is not accounting, tax or financial advice.