Cost-Volume-Profit Analysis (SACE Stage 2 Accounting)
“Apply cost-volume-profit analysis to calculate the break-even point and inform pricing and output decisions”
Cost-volume-profit (CVP) analysis splits costs into fixed and variable, then uses the contribution margin per unit (selling price minus variable cost) to find the break-even point: . Above break-even the business makes a profit.
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What this dot point is asking
You need to classify costs as fixed or variable, calculate contribution margin, find the break-even point in units and dollars, and use CVP to make pricing and output decisions.
Fixed and variable costs
CVP analysis depends on separating costs by behaviour.
Fixed costs stay the same in total regardless of output over a relevant range (for example rent, salaries, insurance). Variable costs change in direct proportion to output (for example materials, packaging, sales commission per unit).
Total cost is .
Contribution margin
Each unit sold contributes toward covering fixed costs and then toward profit.
Once total contribution covers all fixed costs, every further unit's contribution becomes profit.
The break-even point
The break-even point is the level of sales at which total revenue exactly equals total costs, so profit is zero.
To find the units needed for a target profit, add the target to fixed costs:
The margin of safety is how far sales can fall before reaching break-even: . A larger margin of safety means lower risk.
A business sells a single product
Selling price is per unit, variable cost is per unit, and fixed costs are per year.
Each unit sold contributes toward fixed costs first and then toward profit. We find how many units are needed to cover all fixed costs, then extend the analysis to a target profit.
Step 1: Calculate the contribution margin per unit
The contribution margin is what each unit earns toward fixed costs after covering its own variable cost:
Step 2: Find the break-even point in units
At break-even, total contribution exactly covers fixed costs and profit is zero:
Step 3: Find the break-even point in sales dollars
Multiply the break-even units by the selling price to express the result in dollars:
To verify: at units, revenue ; total cost . Profit is zero, confirming break-even.
Step 4: Find the units needed for a target profit of
Add the target profit to fixed costs, because that total must be covered by contributions:
Step 5: Calculate the margin of safety
If the business expects to sell units, the margin of safety is the gap between expected sales and break-even:
Sales could fall by this amount before the business makes a loss.
Final answer: Break-even is units ( in sales). A target profit of requires units. At expected sales of units, the margin of safety is units.
The contribution margin ratio and break-even chart
For businesses that think in sales dollars rather than units, the contribution margin ratio (contribution margin per unit divided by selling price, expressed as a percentage) gives the break-even point directly in dollars: . With a $20 contribution on a $50 price, the ratio is , so of fixed costs needs of sales to break even, agreeing with the unit calculation. SACE also expects you to read a break-even chart: total sales revenue and total cost are both plotted against output, the break-even point is where the two lines cross, the vertical gap to the left of that point is the loss area and the gap to the right is the profit area, and the margin of safety is the horizontal distance from expected sales back to break-even.
Using CVP for decisions
CVP answers practical questions: how a price change shifts break-even, whether a special order is worthwhile if it covers variable cost and contributes to fixed costs, and how much output is needed to reach a profit goal. Raising the selling price increases contribution margin and lowers the break-even point; cutting price does the reverse.
CVP assumes selling price and variable cost per unit are constant, fixed costs are fixed within the relevant range, and (for a multi-product business) the sales mix is stable. Outside the relevant range these assumptions break down, so CVP is a planning guide, not an exact prediction.
Dividing fixed costs by the selling price instead of by the contribution margin. Break-even uses contribution margin per unit (), because only the contribution is available to cover fixed costs. Using the full selling price understates the number of units needed and gives a misleadingly low break-even point.
Exam-style questions
Questions in the style of SACE Board exam questions on this dot point, each with a worked answer. They are written by ExamExplained unless tagged "Past paper"; the year shows the paper a question is modelled on.
2022 SACE Stage 2-style2 marksCalculate the break-even point for 2022 for Espress Yourself's coffee machines. (Selling price $950 per unit; variable costs per unit: cost price $175 and delivery expense $5; fixed costs $130,000.)Show worked answer →
Break-even point (in units) = fixed costs / contribution margin per unit.
Step 1: contribution margin per unit = selling price - total variable cost per unit = 950 - (175 + 5) = 950 - 180 = $770.
Step 2: break-even units = 130,000 / 770 = 168.83, which rounds up to 169 units, because a part unit cannot be sold and 168 would not quite cover fixed costs.
At 169 machines sold, total contribution covers the $130,000 fixed costs and profit is zero.
Markers reward including both variable costs (cost price and delivery) in the contribution margin, the correct formula, and rounding up to the next whole unit.
2022 SACE Stage 2-style4 marksFrom 10 July 2022 the supplier will increase the cost price of coffee machines from $175 to $200 per unit. Discuss the effects this change will have on the break-even point for sales of coffee machines and on the profitability of selling these coffee machines.Show worked answer →
The cost price is a variable cost, so raising it from $175 to $200 changes the contribution margin per unit.
Effect on break-even point: new variable cost per unit = 200 + 5 = $205, so contribution margin falls from $770 to 745. Break-even = 130,000 / 745 = 175 units (rounded up), higher than the previous 169. The business must now sell more machines to cover the same fixed costs.
Effect on profitability: with a lower contribution margin, each machine contributes $25 less, so total profit falls at any given sales level unless the business raises its selling price or cuts other costs. Margin of safety also shrinks.
Markers reward recalculating the contribution margin, showing the higher break-even, and explaining that profit per unit and total profit fall (and that the selling price may need to rise to protect margin).
Practise this
Sources & how we know this
- Stage 2 Accounting subject outline (2025 onwards) — SACE Board
- Stage 2 Accounting: external assessment — SACE Board