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Principles of Accounting · Cost and management accounting

Interpreting cost-volume-profit scenarios

A question changes one figure and asks what happens, and you restart from scratch each time.

A scenario question keeps most of the base case and changes one figure. Recalculate contribution, then break-even units, and compare with the original answer.

This lesson follows calculating contribution and break-even point and is part of SPM Accounting cost and management accounting.

What is the base case?

The cake stall sells at RM25. Ingredients and a box use RM15 of each sale, and rent and salary total RM4 500 for the month. Contribution is RM10, and break-even is 450 cakes.

Worked example: three what-if scenarios

Each scenario changes one thing. The unchanged figures stay as they were.

Scenario Contribution (RM) Fixed costs (RM) Break-even units
Base case 10 4 500 450
A: selling at RM23 8 4 500 4 500 ÷ 8 = 562.5, round up to 563
B: variable items fall to RM13 12 4 500 4 500 ÷ 12 = 375
C: fixed items rise to RM5 400 10 5 400 5 400 ÷ 10 = 540

In scenario A, 562 cakes give a contribution of 562 × 8 = RM4 496, which is RM4 short. The 563rd cake covers it, so the answer is 563.

A price change or a variable cost change moves contribution. A fixed cost change moves the amount that contribution has to cover.

The mistake that rounds down

It is tempting to round 562.5 down to 562 because the number looks close. At 562 cakes the stall is still RM4 short of break-even.

Break-even means all costs are covered, and a lower whole number leaves a shortfall, so always round up.

Check yourself

Each unit sells for RM20 and uses RM12 of variable items, and the fixed items total RM3 200. Find the break-even units.

Then fixed costs rise by 10%. What is the new break-even? Also find the units needed for a profit of RM2 000 at the original fixed costs.

Answer

Contribution = 20 − 12 = RM8. Break-even = 3 200 ÷ 8 = 400 units.

Fixed costs rise to 3 200 × 1.10 = RM3 520. New break-even = 3 520 ÷ 8 = 440 units.

Target profit of RM2 000: (3 200 + 2 000) ÷ 8 = 5 200 ÷ 8 = 650 units.

What to study next

Practise these skills in the chapter practice set. To connect break-even to cash timing, read preparing a simple cash budget.

For a teacher to go through your scenario working, see online one-to-one Accounting tuition.

Common questions

How do I handle a question that changes one cost?

Rebuild only the line that changed, then recalculate contribution and break-even. Keep every other figure from the base case so you can see the effect of that single change.

Why do I round break-even units up?

You cannot sell part of a unit, and selling the lower whole number would not reach break-even. Round up to the next whole unit, then check that contribution covers the fixed costs.

Does a lower selling price always help sales?

The question will say what happens to demand, if anything. Without that information, the lesson only shows what happens to contribution and the break-even point, not to the number sold.

What is a target profit question?

It asks how many units are needed to earn a chosen profit. Add the target to fixed costs and divide by contribution per unit.

If scenario questions feel like new problems each time, a one-to-one Accounting teacher can train you to change only one line of the base case and read the effect.

  • Online one-to-one lessons for your child with an experienced teacher.
  • Your first class is a one-hour trial, from RM50. The fee is agreed before you book.
  • Happy with the teacher? Continue with lessons of about 1.5 hours. If not, ask for another teacher.