Understanding Costs, Revenue, and Profit Revision Notes | GCSE AQA Business

1. Why Costs, Revenue, and Profit Matter

Every business decision — from hiring staff to setting prices — comes down to one question: will this make us money? To answer that, you need to understand three things: what money comes in (revenue), what money goes out (costs), and what is left over (profit or loss).

These are not abstract accounting concepts. They are the difference between a business that survives and one that closes. A business can have high revenue and still make a loss if its costs are even higher — something many students overlook.

AQA examiners regularly ask you to calculate profit, identify cost types, and then evaluate what the figures mean for the business. Getting comfortable with these calculations now means you can focus on the higher-mark analysis in the exam.

2. Types of Costs: Fixed and Variable

Not all costs behave the same way. Some costs stay the same no matter how much a business produces. Others rise and fall with output. Knowing which is which is a core AQA requirement — and examiners test it directly.

Think of it this way: if a business produces zero units, fixed costs still appear on the bill. Variable costs, on the other hand, would be zero at zero output — because no materials are used and no piece-rate wages are earned.

This distinction matters when a business is deciding whether to expand production. Fixed costs are already paid, so producing more units spreads them across a larger output — reducing the fixed cost per unit. Variable costs, however, keep rising with each extra unit produced.

3. Total Costs and Revenue

Once you can identify fixed and variable costs separately, combining them gives you total costs — the full amount a business spends to operate at a given level of output. This is the figure you compare against revenue to find profit or loss.

Revenue is calculated before any costs are taken away. This is a critical distinction. A business with £500,000 in revenue sounds successful — but if its total costs are £520,000, it is actually making a £20,000 loss.

Look at the chart carefully. At 100 units, revenue is £2,000 but total costs are £6,000 — the business is making a significant loss. By 500 units, revenue has reached £10,000 while total costs are £10,000 — the business has broken even. This shows why output level is a critical business decision.

Notice also that fixed costs stay flat across all output levels — the bar for fixed costs is identical at every point. Variable costs, by contrast, grow steadily. This visual pattern is exactly what examiners expect you to describe when asked to 'outline the difference between fixed and variable costs'.

4. Calculating Profit and Loss

With revenue and total costs established, calculating profit is the final step. Profit tells a business whether it is financially viable — and it tells shareholders whether their investment is generating a return.

Worked example: Calculating Total Costs, Revenue, and Profit

Priya runs a candle-making business. Her fixed costs are £4,000 per month. Each candle costs £2 in materials (variable cost). She sells each candle for £7. In November, she produces and sells 1,500 candles. Calculate her total costs, revenue, and profit for November.

1. Total Variable Costs = Variable Cost per Unit x Units Produced = £2 x 1,500 = £3,000 — Variable costs rise with output. Each candle uses £2 of materials, so 1,500 candles use £2 x 1,500 = £3,000 in total.
2. Total Costs = Fixed Costs + Total Variable Costs = £4,000 + £3,000 = £7,000 — Add the fixed costs (which do not change with output) to the total variable costs to get the full cost of operating at this output level.
3. Revenue = Selling Price x Units Sold = £7 x 1,500 = £10,500 — Revenue is calculated before any costs are deducted. Priya sells every candle she produces, so units sold equals units produced here.
4. Profit = Revenue - Total Costs = £10,500 - £7,000 = £3,500 — The result is positive, so Priya makes a profit of £3,500 in November. If the result had been negative, it would be a loss.
5. Profit per unit = £7 - £2 = £5 contribution per candle. £5 x 1,500 = £7,500. £7,500 - £4,000 fixed costs = £3,500. — This alternative route confirms the answer. Each candle contributes £5 towards fixed costs and profit. Once fixed costs are covered, the remainder is profit.

Answer: Total Variable Costs = £3,000. Total Costs = £7,000. Revenue = £10,500. Profit = £3,500.

Notice the structure of that calculation: variable costs first, then total costs, then revenue, then profit. AQA mark schemes award method marks at each stage — so even if you make an arithmetic error, you can still earn marks for correct method. Always show your working.

Worked example: Analysing the Impact of Rising Costs on Profit

Mohammed's printing business has fixed costs of £6,000 per month. Variable costs are £4 per unit. He sells each unit for £10. In December he sells 2,000 units. In January, his paper supplier raises prices, increasing variable costs to £6 per unit. Output and selling price remain the same. Calculate profit for both months and analyse the impact of the cost increase.

1. Total Variable Costs = £4 x 2,000 = £8,000. Total Costs = £6,000 + £8,000 = £14,000 — Fixed costs remain at £6,000. Variable costs at £4 per unit across 2,000 units = £8,000.
2. Revenue = £10 x 2,000 = £20,000. Profit = £20,000 - £14,000 = £6,000 — December profit is £6,000. This is the baseline to compare against January.
3. Total Variable Costs = £6 x 2,000 = £12,000. Total Costs = £6,000 + £12,000 = £18,000 — Variable costs have risen from £4 to £6 per unit. Fixed costs are unchanged at £6,000. Total costs increase by £4,000.
4. Revenue = £10 x 2,000 = £20,000. Profit = £20,000 - £18,000 = £2,000 — Revenue is unchanged because price and output are the same. But profit has fallen from £6,000 to £2,000 — a drop of £4,000.
5. Profit fell by £4,000 (from £6,000 to £2,000) — a 66.7% reduction. Mohammed could respond by raising his selling price, finding a cheaper supplier, or increasing output to spread fixed costs. — This shows how a rise in variable costs directly squeezes profit margins. Mohammed faces a stakeholder conflict: raising prices may lose customers, but absorbing the cost increase reduces returns to the business owner.

Answer: December profit: £6,000. January profit: £2,000. The £2 per unit rise in variable costs reduced profit by £4,000, highlighting how sensitive profitability is to changes in variable costs.

5. Exam Technique and Common Mistakes

Calculation questions on costs, revenue, and profit are among the most reliable mark-earners in the AQA paper — if you follow the right structure. The most common reason students lose marks is not getting the maths wrong; it is failing to show the method clearly or misidentifying which cost type is which.

When a question asks you to 'explain' the impact of a cost change, a one-line answer will not reach the top marks. You need a chain of reasoning: the cost rises, total costs increase, profit falls, and this affects the business's ability to invest or reward shareholders. Each link in that chain earns marks.

For evaluate or discuss questions, remember to consider both sides. A rise in variable costs is damaging to profit, but a business might respond by passing costs on to customers through higher prices — which has its own consequences for demand and competitiveness. Showing that awareness is what separates a Level 2 response from a Level 3.