Profit in absolute terms says little: a profit of 855 is excellent for a corner shop and disastrous for a large manufacturer. Profitability ratios put profit in context — relative to sales (margins) or to the resources used to produce it (returns). They are central to valuation, lending and management decisions.
What you will learn
- Calculate gross, operating, EBITDA and net profit margins
- Calculate return on assets, return on equity and return on capital employed
- Interpret margins and returns in industry context
- Recognise distortions from one-off items, leverage and accounting choices
Margins: profit per unit of sales
Profit margins
Gross profit margin = Gross profit ÷ Revenue
Operating profit margin = Operating profit (EBIT) ÷ Revenue
EBITDA margin = (EBIT + Depreciation and amortisation) ÷ Revenue
Net profit margin = Net profit ÷ Revenue
Each margin reflects a different layer of the business:
- Gross margin — pricing power and production or purchasing efficiency.
- Operating margin — overall operating efficiency, including selling and administrative costs.
- EBITDA margin — operating performance before non-cash depreciation and amortisation; useful for comparing companies with different asset ages, but not a measure of cash flow because it ignores capital expenditure, working capital and tax.
- Net margin — what is left for shareholders after interest and tax.
Returns: profit relative to resources
Return ratios
Return on assets (ROA) = Net profit ÷ Average total assets
Return on equity (ROE) = Net profit ÷ Average shareholders' equity
Return on capital employed (ROCE) = EBIT ÷ Capital employed, where capital employed = total assets − current liabilities (or equity + non-current liabilities)
ROA shows how well all assets generate profit. ROE shows the return to shareholders, and is affected by leverage. ROCE uses operating profit before interest and tax, so it compares operating performance independent of how the company is financed.
Worked example
Worked example: Company A’s profitability, Year 2
Company A (illustrative figures): revenue 9,200; gross profit 3,220; EBIT 1,380; depreciation 330; net profit 855. Total assets 7,000 (start) and 8,000 (end); equity 3,800 (start) and 4,200 (end); current liabilities at year end 1,800.
- Gross margin: 3,220 ÷ 9,200 = 35.0%.
- Operating margin: 1,380 ÷ 9,200 = 15.0%.
- EBITDA margin: (1,380 + 330) ÷ 9,200 = 18.6%.
- Net margin: 855 ÷ 9,200 = 9.3%.
- ROA (average assets 7,500): 855 ÷ 7,500 = 11.4%.
- ROE (average equity 4,000): 855 ÷ 4,000 = 21.4%.
- ROCE (capital employed 8,000 − 1,800 = 6,200): 1,380 ÷ 6,200 = 22.3%.
The calculators for gross, operating and net margins, return on assets and return on equity reproduce these figures.
Interpreting profitability
Compare within the industry. Supermarkets typically earn thin net margins but turn over their assets quickly; software companies often have high margins. A 3% net margin can be excellent in food retail and poor in pharmaceuticals.
Look at the trend. Are margins expanding (pricing power, scale efficiencies) or shrinking (competition, rising costs)?
Compare returns with the cost of capital. A business creates value only if its return on capital exceeds the return investors require — its weighted average cost of capital. A company earning a 9% ROCE with a 12% cost of capital is growing in size but destroying value.
Break ROE down. ROE can be raised by better margins, faster asset use or more debt. DuPont analysis separates these drivers. For Company A, equity finances about 53% of assets, so ROE (21.4%) is almost twice ROA (11.4%).
Adjusting for distortions
- One-off items: gains on asset sales, impairment losses or restructuring costs can make a single year unrepresentative. Analysts often calculate "underlying" margins excluding them, while disclosing what was excluded.
- Accounting policies: depreciation methods, inventory formulas and capitalisation of development costs affect reported profit — see depreciation methods and inventory valuation.
- Average versus year-end balances: for growing companies, year-end balances understate returns. Company A’s ROE is 20.4% on year-end equity but 21.4% on average equity.
- Negative equity makes ROE meaningless.
- Small or loss-making companies: ratios become unstable; focus on the drivers instead.
Quality of profit
High profitability is only valuable if it is real and sustainable. Check whether profits convert into operating cash flow (see cash flow analysis and earnings quality) and whether margins depend on unusual factors such as temporary price spikes or related-party sales.
Common mistakes
- Comparing margins across very different industries.
- Treating EBITDA as cash flow.
- Celebrating a high ROE without checking how much comes from leverage.
- Ignoring one-off items that inflate or depress a single year.
- Mixing average and year-end balances between companies.
Key terms
- Gross margin — gross profit as a percentage of revenue.
- Operating margin — operating profit (EBIT) as a percentage of revenue.
- Net margin — net profit as a percentage of revenue.
- ROA — net profit relative to total assets.
- ROE — net profit relative to shareholders’ equity.
Frequently asked questions
Which profitability ratio matters most?
It depends on the purpose. Equity investors focus on ROE and its sustainability; lenders on operating margins and cash flow; managers on margins by product or segment.
Why can net margin fall while operating margin is stable?
Higher interest costs or a higher tax rate reduce net profit even if operations perform the same — as with Company A’s rising interest expense.
Is EBITDA defined by accounting standards?
No. It is a non-standard measure, and companies calculate it differently. Check the definition used.
Key takeaways
- Margins measure profit per unit of sales at gross, operating, EBITDA and net levels.
- ROA, ROE and ROCE measure profit relative to the resources used.
- Interpret profitability against the industry, the trend and the cost of capital.
- Adjust for one-off items and accounting differences, and check that profits turn into cash.