Understanding how revenue, costs and profit work in a growing business — including gross profit, net profit, profit margins, and the impact of business growth on costs.
Revenue (also called turnover or sales revenue) is the total income a business receives from selling its products or services before any costs are deducted.
As a business grows, revenue typically increases. However, a growing business may also face pressure to lower prices to win more customers, or invest more in production to meet higher demand — both of which affect profit.
When a business is small, finances are relatively simple. As it grows, costs become more complex and the relationship between revenue, costs, and profit becomes harder to manage without proper financial systems.
A larger business must track:
📈 Key idea: Growth doesn't automatically mean higher profit. A business might grow revenue rapidly but see profit margins fall if costs are growing faster than revenue. Managing costs as the business scales is critical.
Costs that do not change with the level of output. They must be paid even if nothing is produced.
Costs that change directly with the level of output — rising as production increases, falling as it decreases.
⚙️ Economies of scale: As a business grows and produces more, the fixed cost is spread over more units — reducing the fixed cost per unit. This is why larger businesses often have lower unit costs than smaller competitors.
| Scale of Business | Fixed Costs | Variable Costs | Unit Cost |
|---|---|---|---|
| Small startup (1,000 units) | £10,000 / yr | £5 per unit | £15 per unit |
| Growing business (10,000 units) | £10,000 / yr | £5 per unit | £6 per unit |
| Large business (100,000 units) | £10,000 / yr | £4 per unit (bulk buy discount) | £4.10 per unit |
As volume grows, fixed costs are spread wider and variable costs may fall thanks to bulk purchasing discounts — both reduce unit cost and improve competitiveness.
Gross profit measures how much money a business makes from selling its products before deducting operating expenses (such as wages, rent, and marketing).
Cost of Sales (also called Cost of Goods Sold / COGS) includes the direct costs of producing the goods: raw materials and direct labour.
| Revenue | £500,000 |
| Cost of Sales (materials + direct labour) | £200,000 |
| Gross Profit | £300,000 |
Net profit (also called operating profit or profit for the year) is gross profit after all other operating expenses have been deducted — including overheads like rent, staff wages, marketing, and interest on loans.
| Gross Profit | £300,000 |
| Operating Expenses (rent, salaries, marketing, etc.) | £180,000 |
| Net Profit | £120,000 |
Profit margins express profit as a percentage of revenue — they show how efficiently a business converts sales into profit.
Using the example above:
📊 Why margins matter: A business might have higher revenue year-on-year but a falling net profit margin — meaning costs are growing faster than sales. Tracking margins shows whether growth is actually profitable.
Click a term, then click its matching definition.
Know all four formulas cold. Revenue = Price × Quantity. Gross Profit = Revenue − CoS. Net Profit = GP − Operating Expenses. Profit Margin = (Profit ÷ Revenue) × 100.
Gross profit vs net profit. Gross profit only deducts cost of sales (direct production costs). Net profit deducts ALL expenses including overheads. A business can have healthy gross profit but poor net profit if overheads are high.
High revenue ≠ high profit. A business can grow revenue but see profit fall if costs rise faster. Always consider the margin, not just the raw profit figure.
Link economies of scale to unit cost. Larger output → fixed costs spread over more units → lower unit cost → better margins. This is a key benefit of business growth.
In calculations, show your working. Even if the final answer is wrong, you can get marks for correct method. Always write out the formula before plugging in numbers.
A business has revenue of £800,000, cost of sales of £320,000, and operating expenses of £240,000. Calculate the net profit margin and explain what it tells us.
Gross Profit = £800,000 − £320,000 = £480,000
Net Profit = £480,000 − £240,000 = £240,000
Net Profit Margin = (£240,000 ÷ £800,000) × 100 = 30%
A net profit margin of 30% means that for every £1 of revenue the business earns, it keeps 30p as profit after all costs. This is a relatively healthy margin and suggests the business is managing its costs effectively relative to its sales. However, to fully assess performance, this should be compared to the previous year's margin and to industry competitors — a falling margin over time would indicate cost pressures outpacing sales growth.