Plain-language questions
Ask for operating expense ratio (OPEX ratio) per month, customer or product in the SQL Explorer with AI. The AI writes the SQL, you see the query and run it yourself; the AI only receives metadata.
KPI · Finance
Operating expense ratio (OPEX ratio): formula and example.
The operating expense ratio, or OPEX ratio, is total operating expenses divided by revenue. Operating expenses are all the costs of running the business apart from cost of goods sold: staff, premises, marketing, IT, depreciation and other overheads. The ratio shows how much of each euro of revenue is spent on the organisation itself.
Operating expense ratio (OPEX ratio) formula
(Staff costs + other operating expenses + depreciation) ÷ revenue × 100%
Worked example
In 2025 Acme Groothandel had €1,800,000 of staff costs, €840,000 of other operating expenses and €240,000 of depreciation, €2,880,000 in total. With revenue of €12,000,000, the OPEX ratio is €2,880,000 ÷ €12,000,000 × 100% = 24%.
Fictitious figures for Acme Groothandel, a sample wholesaler.
How to read this KPI
A falling OPEX ratio means revenue is growing faster than overheads: the business is scaling. A rising ratio can reflect investment in growth, but also costs getting out of hand. Read it together with gross margin: only when gross margin exceeds the OPEX ratio is there a positive operating profit.
Pitfalls with operating expense ratio (OPEX ratio)
- Including depreciation in one period and not in another; state which definition you use.
- Booking costs that belong in cost of goods sold, such as inbound freight, under operating expenses, or the other way round.
- Reading the ratio for a single month when annual costs, such as insurance, were booked in that month.
SQL & DAX
Calculating operating expense ratio (OPEX ratio) in SQL and DAX
Two examples on a fictitious data warehouse for Acme Groothandel: a PostgreSQL query and a measure for a Power BI model. Adjust table and column names to your own model.
SELECT date_trunc('month', entry_date)::date AS month,
SUM(amount) FILTER (WHERE account_group IN ('personnel', 'other_opex', 'depreciation')) AS opex,
SUM(amount) FILTER (WHERE account_group = 'revenue') AS revenue,
ROUND(100.0 * SUM(amount) FILTER (WHERE account_group IN ('personnel', 'other_opex', 'depreciation'))
/ NULLIF(SUM(amount) FILTER (WHERE account_group = 'revenue'), 0), 1) AS opex_ratio_pct
FROM gl_entries
WHERE entry_date >= date_trunc('month', current_date) - interval '12 months'
GROUP BY 1
ORDER BY 1;OPEX = CALCULATE(SUM(GL[Amount]), GL[AccountGroup] IN {"personnel", "other_opex", "depreciation"})
OPEX Ratio % = DIVIDE([OPEX], CALCULATE(SUM(GL[Amount]), GL[AccountGroup] = "revenue"))In ENABLE
Tracking this KPI in ENABLE
In your Power BI dashboard
Define the KPI as a measure in your Power BI model and show it in the portal, with "Last refreshed" next to it. Access profiles and optional row-level security decide who sees which figures.
Custom dashboards (pilot)
Add the KPI as a tile to a custom dashboard, compared with last year. The Dashboard Builder is a pilot and can be switched on per client.
Monthly targets
With the built-in Targets app you set a target for the KPI per month, so you see actuals and target side by side.
FAQ
Frequently asked questions
How do you calculate the operating expense ratio?
Add up all operating expenses, excluding cost of goods sold, divide by revenue and multiply by 100%. With €2,880,000 of operating expenses on €12,000,000 of revenue, the OPEX ratio is 24%.
What is the difference between OPEX and CAPEX?
OPEX are running costs that go straight to the income statement, such as salaries and rent. CAPEX are investments in assets that last several years, such as machinery or software; they reach the income statement gradually through depreciation.
Should depreciation be included in the OPEX ratio?
It depends on the definition: some organisations include depreciation, others use only costs before depreciation. Without depreciation the ratio ties in with EBITDA margin, with depreciation it ties in with operating margin. Choose one definition and stick to it.
Further reading
- KPI libraryFinancial KPIs: formulas and examplesFinancial KPIs show how profitable, liquid and solvent an organisation is. The data usually comes from your accounting package or ERP: general ledger entries, invoices and open items.Read more
- ResourcesHow to build a KPI dashboard: steps and examplesA KPI dashboard is an overview of the key figures you use to steer towards your goals, such as revenue, margin, on-time delivery or absenteeism. A good KPI dashboard does not start with the software, but with the decisions it needs to support. You then choose a limited number of KPIs, define them, sketch the dashboard and only then build it.Read more
- SolutionPower BI dashboard portal: share dashboards securelyShare your Power BI dashboards securely in your own portal, with role-based access.Read more
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