Measurements of business size

Market share is the proportion of total sales in a market that is held by one firm, usually expressed as a percentage — for example, a firm with $6m of sales in a $30m market has a 20% market share.

One method is revenue (sales turnover) — the total value of the firm's sales in a period. It measures size by trading scale, so a business selling $50m of goods is larger by this measure than one selling $5m. It is useful because it reflects actual market activity rather than just workforce size, although it can be inflated by high prices and does not show profit.

A highly automated manufacturer is capital-intensive: it uses machinery and robots to produce, so it needs relatively few workers even though it produces a large volume of output. Measuring its size by the number of employees would therefore make it look small and understate its true scale.

Revenue (sales turnover) measures the value of what the firm actually sells, regardless of how many people it employs. For an automated manufacturer with high output, revenue captures the real scale of its trading activity, making it a fairer basis for comparison with rivals.

Therefore, because employees ignore capital intensity while revenue reflects output, revenue is the more appropriate measure here — although it should ideally be checked against another measure such as capital employed.

Number of employees is a simple, widely-available measure of size, and for some firms it works well. For a labour-intensive business — such as a call centre or a cleaning company — output depends largely on the workforce, so headcount is a reasonable indicator of scale and is easy to obtain and compare.

However, the measure has serious limitations. For a capital-intensive firm, output comes mainly from machinery, so a large, high-output business can employ very few people: measuring by headcount would wrongly make it look small. Headcount is also distorted by part-time and seasonal staff, who inflate the number without adding proportional output, and by outsourcing, which cuts the firm's own employees without reducing its real activity. It also says nothing about revenue, profit or capital.

Therefore the usefulness of employee numbers depends on the type of business: it is a fair measure for labour-intensive firms but misleading for capital-intensive ones. The most reliable approach is to use it alongside measures such as revenue or capital employed, rather than relying on it alone.

There are several ways to measure business size — number of employees, revenue, capital employed, market capitalisation and market share — and each has merits. Revenue is a strong general measure because it reflects trading scale and is available for almost all firms, but it is affected by prices and inflation and ignores profitability. Market share is valuable for comparing firms within the same market, since it shows competitive position, but it requires accurate market-size data and depends on how the market is defined. Market capitalisation captures the stock market's valuation of a firm, but it applies only to plcs and swings with share prices that may not reflect real performance. Number of employees is simple but misleads for capital-intensive firms, while capital employed suits capital-heavy businesses but is hard to value.

The key point is that the 'best' measure depends on the context. To compare two supermarket chains, market share or revenue is most meaningful; to compare automated manufacturers, capital employed or revenue beats headcount; to compare the market value of listed firms, market capitalisation is appropriate.

Judgement. There is no single best measure for all situations. The most defensible position is that the best approach is to choose the measure that fits the industry and the purpose of the comparison, and to use more than one measure together to offset each one's weaknesses. For most general comparisons revenue is the most broadly useful single measure, but it should be supported by market share (for competitive position) or capital employed (for capital-intensive firms). So 'the best way' is not one method but a context-appropriate combination.

Market share — a firm's sales as a percentage of total market sales — is one of several ways to measure size, alongside revenue, employees, capital employed and market capitalisation. It has strong claims to usefulness, but whether it is the most useful depends on the purpose of the measurement.

The case that market share is the most useful measure. Unlike absolute measures, market share shows size relative to rivals, which is what usually matters competitively. A firm can have rising revenue yet a falling market share if the market is growing faster — market share reveals this, while revenue alone hides it. A high market share also signals market power: the ability to influence prices and deter competitors. For comparing firms within the same market, market share is therefore often the single most meaningful indicator of competitive size.

The case that other measures are more useful. First, market share is only meaningful within a defined market; it cannot compare firms across different industries, where revenue or capital employed is needed. Second, it depends heavily on how the market is defined — a firm can look dominant in a narrow market and tiny in a broad one — and on accurate market-size data that may not exist. Third, it says nothing about profitability: a firm can buy market share by cutting prices and making losses. Fourth, for judging the value of a listed company, market capitalisation is more relevant, and for capital-intensive firms capital employed better reflects scale.

Weighing it up (criterion). The usefulness of market share depends on the purpose of the measurement and whether comparisons are within or across markets. For assessing competitive position within a single market, it is arguably the most useful measure. For comparing firms across industries, judging financial value, or assessing profitability, other measures are more useful.

Judgement. Market share is the most useful measure to a significant extent — but only for the specific purpose of comparing competitive position within a defined market. It is not the most useful measure in general, because it cannot compare across industries, ignores profitability, and depends on how the market is defined. The most defensible conclusion is that market share is the best measure of competitive size within a market, but for an overall picture it should be combined with revenue (trading scale) and a profitability measure — so its claim to be the most useful holds only within its proper context.