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How do profitability and efficiency ratios measure how well a business generates profit and uses its assets?

Calculate and interpret gross profit margin, net profit margin, return on assets, return on equity, inventory turnover and accounts receivable turnover, and explain what each reveals

WACE Year 12 Accounting and Finance Unit 4 on profitability and efficiency ratios: gross and net profit margin, return on assets, return on equity, inventory turnover and accounts receivable turnover, with calculation and interpretation of each.

Generated by Claude Opus 4.87 min answerUpdated 2026-06-02

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What this dot point is asking
Profitability ratios
Efficiency ratios
Why "average" is used in turnover ratios
From margin to return: how the ratios connect

What this dot point is asking

SCSA wants you to calculate each ratio, state its units, and interpret what a result means for the business rather than just reporting a number.

Profitability ratios

Gross profit margin isolates the markup on goods sold before operating costs. Net profit margin captures the effect of all expenses. Return on assets shows how efficiently the asset base generates profit, while return on equity shows the return to the owners specifically.

Efficiency ratios

A higher inventory turnover means stock sells quickly, freeing cash and reducing holding costs, though too high may signal lost sales from running out. A higher receivables turnover means customers pay faster. Turnover can be converted into days: 365 divided by the turnover gives the average days stock is held or the average collection period.

Why "average" is used in turnover ratios

Turnover ratios use an average of the opening and closing balance for inventory or receivables, not just the closing figure. The reason is a matching of timing: cost of sales and credit sales are flows measured over the whole period, while a balance sheet figure is a snapshot at one instant. Pairing a full-year flow with a single point-in-time balance can distort the ratio, especially for a seasonal business whose closing stock or receivables may be unusually high or low. Averaging the opening and closing balances gives a figure more representative of the level held across the period, so the turnover better reflects how the business actually used those resources. When a question gives only a closing balance, use it, but state the assumption; when it gives both, average them.

Calculating a profitability and an efficiency ratio

Wren Ltd reports sales $600 000, cost of sales$ 360 000, net profit $54 000, total assets$ 400 000 and average inventory $40 000.

Step 1: Calculate gross profit and gross profit margin

Gross profit is the surplus after removing the cost of the goods sold. It measures how much markup the business earns before any operating expenses are deducted, so it reflects pricing strength and the efficiency of buying or producing inventory.

\text{Gross profit} = 600\,000 - 360\,000 = 240\,000

\text{Gross profit margin} = \frac{240\,000}{600\,000} \times 100 = 40\%

Step 2: Calculate net profit margin

Net profit margin shows what proportion of each sales dollar remains as profit after all expenses have been deducted. Comparing gross and net margins reveals how much of the gross markup is consumed by operating expenses such as wages, rent and administration.

\text{Net profit margin} = \frac{54\,000}{600\,000} \times 100 = 9\%

The drop from 40 per cent to 9 per cent shows operating expenses absorb most of the markup, which is where management should look to improve profitability.

Step 3: Calculate return on assets

Return on assets measures how efficiently the entire asset base generates profit, regardless of how those assets were financed. It shows whether management is deploying the business's resources productively.

\text{Return on assets} = \frac{54\,000}{400\,000} \times 100 = 13.5\%

Step 4: Calculate inventory turnover and interpret

Inventory turnover uses cost of sales rather than revenue because inventory is carried at cost, making a like-for-like comparison. A higher turnover means stock sells quickly, freeing cash and reducing holding costs.

\text{Inventory turnover} = \frac{360\,000}{40\,000} = 9 \text{ times}

Stock turns nine times a year, roughly every 41 days ( $365 \div 9$ ), indicating a moderately fast-moving inventory cycle.

Final answer: Gross profit margin is 40%, net profit margin is 9%, return on assets is 13.5%, and inventory turnover is 9 times (approximately 41 days).

From margin to return: how the ratios connect

Profitability can be read at two levels, and connecting them is where strong interpretation lives. The margins (gross and net) measure profit per dollar of sales, so they speak to pricing and cost control. The returns (on assets and on equity) measure profit relative to the resources used to earn it, so they speak to how productively the business deploys its asset base and its owners' funds. A business can have a high net profit margin yet a low return on assets if it needs a very large asset base to generate each sale, or a modest margin yet a strong return on assets if it turns its assets over quickly. This is why return on assets can be thought of as net profit margin multiplied by asset turnover: a business earns a good return either by making more profit on each sale or by making more sales from each dollar of assets, or both. Reading margins and returns together explains not just how profitable a business is, but why.

Exam-style practice questions

Practice questions written in the style of SCSA exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.

WACE 20228 marksPyree Ltd reports sales

800 000, cost of sales

480 000, net profit

72 000, total assets

600 000, total equity

400 000 and average inventory

48 000. Calculate gross profit margin, net profit margin, return on assets, return on equity and inventory turnover, and comment on what the gap between return on assets and return on equity suggests.

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An 8 mark response needs the five ratios and the comment.

Gross profit. $800\,000 - 480\,000 = 320\,000$ . Gross profit margin $= \frac{320\,000}{800\,000} \times 100 = 40\%$ .

Net profit margin. $\frac{72\,000}{800\,000} \times 100 = 9\%$ .

Return on assets. $\frac{72\,000}{600\,000} \times 100 = 12\%$ .

Return on equity. $\frac{72\,000}{400\,000} \times 100 = 18\%$ .

Inventory turnover. $\frac{480\,000}{48\,000} = 10$ times.

Comment. Return on equity (18 per cent) exceeds return on assets (12 per cent) because the company uses debt: borrowed funds add to the asset base earning returns without adding to equity, so the return is concentrated on a smaller equity base. The gap signals reliance on borrowings. Markers reward all five ratios and a correct explanation of the gearing effect.

WACE 20235 marksExplain why inventory turnover uses cost of sales rather than sales, and explain what a rising inventory turnover and a rising accounts receivable turnover each tell management.

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A 5 mark response needs the cost-matching point and both interpretations.

Cost of sales. Inventory is carried at cost, so the numerator must also be at cost to make a like-for-like comparison. Using sales would include the profit markup that is not in the inventory figure, inflating the ratio and misstating how fast stock turns.

Rising turnovers. A rising inventory turnover means stock is selling faster, freeing cash and cutting holding costs (though too high may risk stockouts and lost sales). A rising accounts receivable turnover means customers are paying more quickly, improving cash flow and reducing the risk of bad debts. Markers reward the cost-matching reason and a sensible interpretation of each rising ratio.