Marginal Costing, Break-even and Decisions
Cost behaviour, contribution, break-even and margin of safety applied to pricing, make-or-buy, additional work and scarce-resource decisions.
How to study A-level Accounting
Build each solution in a fixed order: identify the accounting relationship, record or calculate methodically, reconcile the result, then interpret it for the relevant decision and stakeholder.
Core concepts
Concept 1
Marginal costing separates variable costs from fixed costs and uses contribution to support short-run decisions.
Exam cue: Classify costs by behaviour and relevance before calculating contribution.
Concept 2
Break-even analysis links selling price, variable cost, fixed cost and activity under stated assumptions.
Exam cue: Check whether spare capacity, scarce resources or avoidable fixed costs change the decision.
Concept 3
Relevant-cost decisions consider future cash flows that differ between alternatives, alongside capacity, risk and qualitative factors.
Exam cue: State the assumptions and qualitative consequences after the numerical result.
Risk pitfalls and guardrails
Using full cost automatically for a short-run decision.
Guardrail: Do not select a familiar formula or entry until you have classified the accounts, period, user and decision named in the task.
Treating sunk costs as relevant future costs.
Guardrail: Do not select a familiar formula or entry until you have classified the accounts, period, user and decision named in the task.
Maximising contribution per unit when a different scarce-resource unit is limiting.
Guardrail: Do not select a familiar formula or entry until you have classified the accounts, period, user and decision named in the task.
Memory anchors
Contribution
Contribution equals sales revenue less variable cost.
Break-even
Break-even occurs where total contribution equals fixed cost.
Margin of Safety
Margin of safety is expected activity above break-even activity.
Relevant Cost
A relevant cost is a future cash flow that differs between alternatives.
Sunk Cost
A sunk cost has already been incurred and is not changed by the current decision.
Limiting Factor
When a resource is scarce, compare contribution per unit of that scarce resource.
Checkpoint rule
Do the check-up only after you can summarize each concept in one sentence and identify one dangerous pitfall from memory.
Knowledge Check (after reading)
Short check-up to confirm understanding of this module.
Check-up Questions
A product sells for £48 and has variable cost £29 per unit. What is contribution per unit?
Contribution is £19 per unit and 12,000 units are sold. What total contribution is earned?
Answer all questions to submit.
Next step personalized recommendations
Continue learning
Move forward only after this module is stable.
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