IGCSE Business: Costs, scale of production and break-even analysis (Cambridge 0264) – Revision Notes

These notes condense section 4.4, Costs, scale of production and break-even analysis, of the Cambridge IGCSE Business 0264 syllabus for examination in 2027, 2028 and 2029. They cover 4.4.1 costs, 4.4.2 economies and diseconomies of scale and 4.4.3 break-even analysis. For full explanations and longer worked examples, read the study guide first, then test yourself with the practice questions. The course hub, the checklist lets you tick off progress, and the free diagnostics show weak spots. All businesses below are invented and money is in pounds.

Key definitions

Term	Meaning
Fixed costs	Costs that do not change with output (rent, insurance, managers’ salaries)
Variable costs	Costs that change directly with output (materials, packaging)
Total cost	Total fixed costs + total variable costs
Average cost	Total cost ÷ number of units
Contribution per unit	Selling price per unit − variable cost per unit
Break-even	Output at which total revenue equals total cost: no profit and no loss
Margin of safety	Actual number of sales − break-even number of sales
Economies of scale	Falling average cost as a business increases its scale of production
Diseconomies of scale	Rising average cost because a business has become too large

Formulas

Calculation	Formula	Unit
Total variable cost	variable cost per unit × number of units	money
Variable cost per unit	total variable cost ÷ number of units	money
Total cost	total fixed costs + total variable costs	money
Average cost	total cost ÷ number of units	money per unit
Break-even output	fixed costs ÷ contribution per unit	units
Margin of safety	actual sales − break-even sales	units

These are the forms given in the syllabus’s “Formulas and ratios” section. Revenue is selling price per unit × number of units sold, and profit is total revenue − total costs.

Costs in steps

1. Sort each cost: does it change as output changes? If not, it is fixed. If so, it is variable.
2. Total variable cost = variable cost per unit × units.
3. Total cost = fixed + total variable.
4. Average cost = total cost ÷ units.

Worked reminder. Voxley Candles has fixed costs of £12,000 a month and variable costs of £3 per candle. At 4,000 candles: total variable cost = 3 × 4,000 = £12,000, total cost = 12,000 + 12,000 = £24,000, average cost = 24,000 ÷ 4,000 = £6. Average cost falls as output rises because fixed costs are spread over more units.

Cost data and simple decisions

Decision	What the cost data tells you	What else to check
Price to set	Price must exceed average cost at the expected output for a profit	Rivals’ prices, customers’ willingness to pay
Which product to produce	Compare contribution per unit	Demand, production time, brand image
Continue or stop a product	Does it still contribute towards fixed costs that will continue anyway?	Whether the resources could earn more elsewhere
Choose a supplier	Compare total cost for the quantity needed, including fees	Quality, reliability, payment terms

Economies of scale (average cost falls)

Type	Memory hook
Purchasing	Bulk buying earns discounts
Marketing	Advertising spread over more units
Financial	Bigger firms borrow at lower interest
Managerial	Can afford specialist managers
Technical	Large, efficient machines and mass production

Diseconomies of scale (average cost rises)

Type	Memory hook
Poor communication	Long chains of command, slow or distorted messages
Lack of commitment or loyalty	Workers feel unimportant, so motivation and effort fall
Weak coordination	Sites and departments out of step
Lack of control	Managers cannot supervise everything

Distinction to hold on to. Average cost falling or rising with the scale of production is different from a rise in total cost. Total cost almost always rises with output. What matters is whether it rises faster or slower than output.

Break-even in steps

1. Contribution per unit = selling price − variable cost per unit.
2. Break-even output = fixed costs ÷ contribution per unit. Round up to a whole unit.
3. Margin of safety = actual sales − break-even output.
4. Profit at a level of output = contribution per unit × units − fixed costs.

Worked reminder. Voxley sells candles at £9. Contribution = 9 − 4 = £5 when variable cost is £4 and fixed costs are £20,000. Break-even output = 20,000 ÷ 5 = 4,000 candles. With sales of 5,100, margin of safety = 1,100 candles and profit = 5,100 × 5 − 20,000 = £5,500.

Effect of changes (same Voxley figures)

Change	Calculation	New break-even output
Price up to £10	20,000 ÷ (10 − 4) = 20,000 ÷ 6	3,334 candles
Fixed costs up to £24,000	24,000 ÷ 5	4,800 candles
Variable cost down to £3.50	20,000 ÷ (9 − 3.50) = 20,000 ÷ 5.50	3,637 candles

The direction rule: a higher price or lower costs move break-even down (left on the chart). A lower price or higher costs move it up (right). Always re-check the margin of safety against expected sales.

Break-even chart: what to draw and read

• Horizontal axis: output. Vertical axis: money (revenue and costs).
• Fixed costs: a horizontal line.
• Total costs: starts at the fixed cost level on the vertical axis, then rises.
• Total revenue: starts at the origin.
• Break-even point: where total revenue and total costs cross. Read the output down to the horizontal axis.
• Profit: the gap to the right, with revenue above total cost. Loss: the gap to the left, with revenue below total cost.
• Margin of safety: the horizontal distance between actual output and break-even output.

Amend the chart for	What moves
Higher price	Revenue line steeper
Higher fixed costs	Fixed cost and total cost lines both shift up
Higher variable cost per unit	Total cost line steeper

To complete a missing line, plot two points (one at zero output) and join them with a ruler.

Limitations of break-even analysis

Assumes all output is sold, price and variable cost per unit stay constant, fixed costs stay fixed at all output levels, and costs and revenue can be forecast accurately. Works best for one product. Ignores competitors and changes in demand. A chart shows where break-even is, but does not say whether the business will reach it.

Answering in the exam

• Calculate: write the formula, substitute the figures, give the answer with its unit (units, or money).
• Define and State: a short, precise statement is enough.
• Explain: give the point, then the reason, then link it to the business in the question.
• Justify: support a decision with evidence and set out a reason against it too, then decide. For a break-even decision, quote the new break-even output, compare it with expected sales and comment on whether customers will really buy at that level.

Quick self-test

1. Define fixed costs.
2. A firm has total fixed costs of £15,000 and variable costs of £6.20 per unit. Calculate its total cost and average cost at 2,500 units.
3. Elmbridge Bags sells a bag for £40. Variable cost is £28 and fixed costs are £36,000. Calculate break-even output.
4. Elmbridge sells 3,400 bags. Calculate the margin of safety.
5. Calculate Elmbridge’s profit at 3,400 bags.
6. State two types of economy of scale.
7. State two causes of diseconomies of scale.
8. A product sells for £15 and has variable costs of £9 per unit. Fixed costs are £18,000. Calculate break-even output.
9. Explain why a price rise lowers break-even output.
10. State one limitation of break-even analysis.

Answers

1. Costs that do not change when output changes, such as rent.
2. Total variable cost = 6.20 × 2,500 = £15,500. Total cost = 15,000 + 15,500 = £30,500. Average cost = 30,500 ÷ 2,500 = £12.20.
3. Contribution = 40 − 28 = £12. Break-even = 36,000 ÷ 12 = 3,000 bags.
4. 3,400 − 3,000 = 400 bags.
5. 3,400 × 12 − 36,000 = 40,800 − 36,000 = £4,800.
6. Any two from purchasing, marketing, financial, managerial, technical.
7. Any two from poor communication, lack of commitment or loyalty from employees, weak coordination, lack of control.
8. Contribution = 6. Break-even = 18,000 ÷ 6 = 3,000 units.
9. Each unit then contributes more towards fixed costs, so fewer units are needed to cover them.
10. For example: it assumes everything made is sold at a constant price.

Where marks are usually lost

• Dividing fixed costs by selling price instead of contribution per unit.
• Writing break-even output in money instead of units.
• Using actual sales as the break-even figure when finding margin of safety, or subtracting the wrong way round.
• Calling variable cost per unit the “average cost”.
• Starting the total cost line at the origin on a chart.
• Naming an economy of scale but never saying how average cost falls.
• Saying “bigger firms are better” without any diseconomies of scale.
• Judging a price change from break-even output alone, with no comment on demand.
• Listing limitations in general terms, not linked to the business in the question.

Frequently asked questions

How do you draw a break-even chart? Put output on the horizontal axis and money on the vertical axis. Draw fixed costs as a horizontal line, start total costs at the fixed cost level and total revenue at the origin; break-even is where total revenue and total costs cross.

What happens to break-even output if the price rises? A higher price, or lower costs, moves break-even output down. A lower price or higher costs move it up, but a price change may also change how many units customers buy.

What are the limitations of break-even analysis? It assumes all output is sold, the price and variable cost per unit stay constant and fixed costs stay fixed. It suits one product, uses forecasts that may be wrong and ignores the market.

Is variable cost per unit the same as average cost? No. Average cost is total cost divided by output, so it includes a share of fixed costs. Calling variable cost per unit the “average cost” is a common error.

Official syllabus

Cambridge IGCSE Business 0264 syllabus for examination in 2027, 2028 and 2029, Cambridge University Press & Assessment, section 4.4 and the Formulas and ratios section.