IGCSE Business Studies (0450)

Break-even charts: construct, interpret, calculate and limitations

What this topic tests, the mistakes that cost marks, and one exam-style question worked through step by step.

Key ideas and common mistakes

Recognize that a break-even chart always includes a total revenue line, not just cost lines.
Common mistake: Students often confuse this with only plotting costs or forget that revenue must be shown to find the break-even point.
Margin of safety is the amount by which actual sales exceed break-even sales.
Common mistake: Students often confuse it with profit or with the break-even point itself, rather than recognizing it as the gap between current and break-even sales.
On a break-even chart, the total revenue line starts at zero and rises steeply (since no sales means no revenue), while the total cost line starts above zero at fixed costs and rises less steeply.
Common mistake: Confusing these lines is the common error.
Break-even output is found where total revenue equals total cost (the intersection of TR and TC lines), not where either equals fixed cost or where the lines are closest together.
The break-even revenue is found by identifying where total revenue equals total cost on the chart and reading the corresponding value on the revenue (money) axis.
Common mistake: Students often misread the axis or pick the quantity instead of the revenue.

Define 'margin of safety'.

Try it first, then show the working

The difference between current (actual) sales/output and break-even sales/output
It shows how far sales can fall before break-even (a loss) is reached

Answer: The difference between a business's current level of sales and its break-even level of sales.

7 exam-style questions on Break-even charts: construct, interpret, calculate and limitations, each marked to the scheme.