Why is "Drawing the fixed-cost line sloping upward on the break-even chart" a common mistake in Break-even?

Why it happens: Students draw all cost lines rising. How to avoid it: Fixed costs are HORIZONTAL (they don't change with output). The TOTAL cost line slopes up, starting at the fixed-cost value. This is the most-penalised chart error. Source: WBS12 Examiner Reports

Why is "Dividing by the wrong figure in the break-even formula" a common mistake in Break-even?

Why it happens: Students divide by price or total variable cost. How to avoid it: Break-even output = fixed costs ÷ contribution PER UNIT. Not price, not total variable cost.

Why is "Confusing contribution with profit" a common mistake in Break-even?

Why it happens: Both are 'money made per unit'. How to avoid it: Contribution per unit ignores fixed costs; profit = total contribution MINUS fixed costs.

Why is "Ignoring a negative margin of safety" a common mistake in Break-even?

Why it happens: Students expect a positive number. How to avoid it: A negative margin of safety means output is BELOW break-even — the firm is making a LOSS, a serious warning.

Why is "Treating break-even as certain, ignoring its assumptions" a common mistake in Break-even?

Why it happens: The chart looks precise. How to avoid it: Break-even assumes constant price and costs and that all output is sold — flag these limitations in evaluation.

Why is "Answering a 6-mark 'Analyse two…' question with only one point" a common mistake in Break-even?

Why it happens: Students develop the first point and forget the command needs two. How to avoid it: 6-mark Analyse = Knowledge 2, Application 2, Analysis 2 — give TWO points, each developed (2+2+2). Source: WBS12 mark schemes

Edexcel International A Levels Business (XBS11-YBS11)

Break-even

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Detailed Study Notes

Detailed notes on Financial Planning for Edexcel International A Levels Business, covering key concepts, explanations, examples, and exam-focused revision points.

Break-even: Contribution, BEP & Margin of Safety — Edexcel IAL Business (WBS12) Study Notes

Break-even tells a business how much it must sell to cover its costs. Learn contribution, the break-even formula, the margin of safety, and how to draw and read a break-even chart — the guaranteed Calculate and Construct questions in WBS12. Master the one chart error examiners penalise most (a sloping fixed-cost line) and how to use break-even to make decisions.

At a glance

Break-even output is the level of sales at which total revenue exactly equals total costs — no profit, no loss.
Contribution per unit = selling price − variable cost per unit — what each unit 'contributes' towards fixed costs and then profit.
Break-even output = fixed costs ÷ contribution per unit (the formula to memorise).
Margin of safety = actual output − break-even output — how far sales can fall before a loss.
Above break-even the firm makes a profit; below it, a loss.
A break-even chart plots fixed costs, total costs and total revenue against output; they cross at the break-even point (BEP).
Profit = (contribution per unit × units sold) − fixed costs, i.e. total contribution minus fixed costs.
Break-even is a useful planning tool but rests on assumptions (constant price and costs) that may not hold.

What you’ll learn

Mapped to the Pearson Edexcel International A Levels XBS11-YBS11 syllabus (2018-2026).

2.3.2 — Calculate contribution per unit and total contribution.
2.3.2 — Calculate break-even output using the formula.
2.3.2 — Calculate the margin of safety.
2.3.2 — Construct and interpret a break-even chart.
2.3.2 — Evaluate the usefulness and limitations of break-even analysis.

Contribution and the break-even formula

Contribution per unit is price minus variable cost; break-even output is fixed costs divided by contribution per unit.

Contribution is the key idea. Contribution per unit is what each unit sold contributes towards paying off fixed costs (and, once they're covered, towards profit):

$\text{Contribution per unit} = \text{selling price} - \text{variable cost per unit}$

Break-even output is the number of units at which total contribution exactly covers fixed costs — total revenue = total costs, so profit is zero:

$\text{Break-even output} = \frac{\text{fixed costs}}{\text{contribution per unit}}$

Worked example. A firm sells at £4 per unit, with variable cost £2 per unit and fixed costs £10,000:

$\text{Contribution} = 4 - 2 = £2 \text{ per unit}$ $\text{Break-even output} = \frac{10{,}000}{2} = 5{,}000 \text{ units}$

So the firm must sell 5,000 units to break even. Every unit sold above 5,000 adds £2 of profit; every unit below leaves part of fixed costs uncovered — a loss.

Profit from contribution. Once you know contribution, profit is easy:

$\text{Profit} = (\text{contribution per unit} \times \text{units sold}) - \text{fixed costs}$

At 8,000 units: profit = (£2 × 8,000) − £10,000 = £16,000 − £10,000 = £6,000.

Always show working and units — a 4-mark Calculate rewards method even if the final number slips.

Contribution per unit = selling price − variable cost per unit.
Break-even output = fixed costs ÷ contribution per unit.
Above BEP = profit; below BEP = loss.
Profit = (contribution per unit × units) − fixed costs.
Show the formula, working and units on every Calculate.

See the full worked example for break-even →

Margin of safety

The margin of safety is how far actual output exceeds break-even — how much sales could fall before a loss.

The margin of safety shows how much a business's sales could fall before it starts making a loss:

$\text{Margin of safety} = \text{actual output} - \text{break-even output}$

Worked example. With break-even at 5,000 units and actual output of 8,000 units:

$\text{Margin of safety} = 8{,}000 - 5{,}000 = 3{,}000 \text{ units}$

So sales could fall by 3,000 units before the firm made a loss — a comfortable cushion.

Interpreting it:

A large margin of safety = a safe, resilient position; sales can drop a lot before a loss.
A small margin of safety = risky; even a small fall in sales pushes the firm into loss.
A negative margin of safety = the firm is below break-even, already making a loss — a serious warning sign.

Why it matters. The margin of safety turns break-even into a risk measure. A business can improve it by raising output/sales, cutting fixed costs (lowers break-even), or increasing contribution (raise price or cut variable cost). Linking a firm's margin of safety to its risk and resilience is a strong AO3 point.

Margin of safety = actual output − break-even output.
Large margin = safe; small margin = risky; negative = making a loss.
It measures how far sales can fall before a loss.
Improve it by raising sales, cutting fixed costs, or raising contribution.
Links break-even to risk and resilience.

The break-even chart

A break-even chart plots fixed costs, total costs and total revenue against output; they meet at the break-even point.

A break-even chart shows costs and revenue at every level of output. The Construct question requires it drawn precisely.

The three lines:

Fixed costs (FC) — a horizontal line at the fixed-cost value (they don't change with output). This is the line examiners most often see drawn wrongly.
Total costs (TC) — starts at the fixed-cost value on the y-axis (at zero output, TC = FC) and slopes up as variable costs are added.
Total revenue (TR) — starts at the origin (zero output = zero revenue) and slopes up more steeply than TC.

Reading the chart:

The break-even point (BEP) is where TR crosses TC — drop a line to the output axis to read the break-even output.
Left of BEP: TC is above TR → the vertical gap is the loss.
Right of BEP: TR is above TC → the vertical gap is the profit.
The margin of safety is the distance on the output axis from the BEP to the actual output.

Full-marks Construct: label both axes (with units), draw all three lines correctly (FC horizontal, TC starting at FC, TR from the origin), and label the BEP.

FC = horizontal line; TC = starts at FC and slopes up; TR = from origin, steeper.
BEP = where TR crosses TC.
Left of BEP = loss (TC > TR); right of BEP = profit (TR > TC).
Margin of safety = BEP to actual output on the output axis.
Construct marks need labelled axes, correct lines, and a labelled BEP.

See the full worked example for break-even →

Using and evaluating break-even

Break-even helps set targets and assess risk, but rests on simplifying assumptions that may not hold.

Uses of break-even analysis:

Set a sales target — the minimum the firm must sell to avoid a loss.
Assess risk — via the margin of safety.
Support decisions — model the effect of a price change, cost change or investment on the break-even point ('what-if' analysis).
Support finance applications — banks like to see a break-even analysis in a business plan.

Limitations (essential for the top marks):

Assumes everything is constant — that price and costs per unit stay the same at all output levels. In reality, discounts for bulk buyers lower price, and costs change with output.
Assumes all output is sold — but firms may not sell everything they make.
Single product — simple break-even assumes one product/price; multi-product firms are more complex.
Static — it's a snapshot; a dynamic market quickly changes the numbers.

The judgement. Break-even is a useful, simple planning and decision tool — especially for a start-up or a specific decision — but it is a simplification. Its reliability depends on how far its assumptions (constant price/costs, all output sold) hold for the specific business. The best answers use break-even to reach a decision and note its limitations for the firm in question.

Uses: set sales targets, assess risk, model price/cost changes, support finance bids.
Assumes constant price and costs per unit at all output levels.
Assumes all output is sold; assumes a single product.
It's a static snapshot — dynamic markets change the numbers.
Use break-even to decide AND note its limiting assumptions.

Quick recap

Contribution per unit = selling price − variable cost per unit.
Break-even output = fixed costs ÷ contribution per unit.
Margin of safety = actual output − break-even output (negative = a loss).
Profit = (contribution per unit × units) − fixed costs.
Chart: FC horizontal, TC from FC, TR from origin; BEP where TR crosses TC.
Break-even is useful but assumes constant price/costs and all output sold.

Memorise this

Verbatim phrases and definitions Edexcel mark schemes credit.

Contribution per unit = selling price − variable cost per unit.
Break-even output = fixed costs ÷ contribution per unit.
Margin of safety = actual output − break-even output.
Profit = (contribution per unit × units sold) − fixed costs.
On a break-even chart, the fixed-cost line is horizontal, the total-cost line starts at the fixed-cost value, and the total-revenue line starts at the origin; they break even where total revenue crosses total cost.

How it’s examined

Examined in Unit 2 (WBS12) — one of the two most common quantitative questions every series. Expect a 4-mark Calculate of break-even output and/or margin of safety (show working, include units), and a 4-mark Construct of a break-even chart (labelled axes, three correct lines, labelled BEP). Also a 2-mark Define ('contribution', 'margin of safety'); and a 6-mark Analyse — often the implications of a negative margin of safety (chain: below BEP → fixed costs uncovered → loss → cash outflow → needs finance → risk of failure). Break-even feeds the Assess/Evaluate on its usefulness. Examiner reports flag: the fixed-cost line drawn sloping (it's horizontal), dividing by the wrong figure in the formula, and confusing contribution with profit. Show working, draw FC flat, and evaluate the assumptions.

Sources: Pearson Edexcel International Advanced Level Business (XBS11/YBS11) Specification, Issue 1; Edexcel IAL Business WBS12 Examiner Reports; Edexcel IAL Business WBS12 mark schemes. Last reviewed 2026-07-08.

Take this whole topic with you

Step-by-step worked examples — Break-even

Step-by-step solutions to past-paper-style questions on break-even, written exactly the way a tutor would explain them at the board.

Question type:

1Calculate contribution per unit
Getting startedDirect calculation• WBS12 Section A style — Calculate (4 marks: Knowledge 1, Application 2, Analysis 1)• contribution, calculate, AO2
Question
GadgetCo sells a gadget at £4 per unit with variable costs of £2 per unit. Calculate the contribution per unit. (2 marks)
Step-by-step solution
1. Step 1
  State the formula.
  $\text{Contribution per unit} = \text{selling price} - \text{variable cost per unit}$
2. Step 2
  Substitute and calculate.
  $= 4 - 2 = £2 \text{ per unit}$
Answer
Contribution per unit = £2.
Examiner tip
Contribution = price − variable cost per unit. It's what each unit contributes to fixed costs, then profit — NOT profit itself.
2Calculate break-even output
Getting startedDirect calculation• WBS12 Section A style — Calculate (4 marks: Knowledge 1, Application 2, Analysis 1)• break-even, calculate, AO2
Question
GadgetCo has fixed costs of £10,000 and a contribution of £2 per unit. Calculate its break-even output. (4 marks)
Step-by-step solution
1. Step 1
  State the formula (Knowledge).
  $\text{Break-even output} = \frac{\text{fixed costs}}{\text{contribution per unit}}$
2. Step 2
  Substitute (Application).
  $= \frac{10{,}000}{2}$
3. Step 3
  Calculate and add the unit (Analysis).
  $= 5{,}000 \text{ units}$
Answer
Break-even output = 5,000 units.
Examiner tip
4 marks: formula (Knowledge 1), correct substitution (Application 2), answer in units (Analysis 1). Divide fixed costs by contribution PER UNIT — not by price or total variable cost.
3Calculate the margin of safety
Building confidenceDirect calculation• WBS12 Section A style — Calculate (4 marks: Knowledge 1, Application 2, Analysis 1)• margin of safety, calculate, AO2
Question
GadgetCo's break-even output is 5,000 units and it currently sells 8,000 units. Calculate its margin of safety. (4 marks)
Step-by-step solution
1. Step 1
  State the formula (Knowledge).
  $\text{Margin of safety} = \text{actual output} - \text{break-even output}$
2. Step 2
  Substitute (Application).
  $= 8{,}000 - 5{,}000$
3. Step 3
  Calculate and interpret (Analysis). 3,000 units — sales could fall by 3,000 before a loss.
  $= 3{,}000 \text{ units}$
Answer
Margin of safety = 3,000 units (sales can fall 3,000 before a loss).
Examiner tip
Margin of safety = actual − break-even output. Interpret it: a large margin is safe; a negative one means the firm is making a loss.
4Calculate profit using contribution
Building confidenceDirect calculation• WBS12 Section A style — Calculate (4 marks: Knowledge 1, Application 2, Analysis 1)• profit, contribution, AO2
Question
GadgetCo sells 8,000 units at a contribution of £2 each, with fixed costs of £10,000. Calculate its profit. (4 marks)
Step-by-step solution
1. Step 1
  State the formula (Knowledge).
  $\text{Profit} = (\text{contribution per unit} \times \text{units}) - \text{fixed costs}$
2. Step 2
  Substitute (Application).
  $= (2 \times 8{,}000) - 10{,}000$
3. Step 3
  Calculate (Analysis).
  $= 16{,}000 - 10{,}000 = £6{,}000$
Answer
Profit = £6,000.
Examiner tip
Total contribution (£16,000) minus fixed costs (£10,000) = profit. Don't stop at total contribution — subtract fixed costs.
5Construct a break-even chart
StretchGraph or diagram• WBS12 Section A/B style — Construct (4 marks: Knowledge 1, Application 2, Analysis 1)• break-even chart, construct, AO2
Question
Describe how to construct a break-even chart for GadgetCo (FC £10,000, price £4, VC £2 per unit), and what earns full marks. (4 marks)
Step-by-step solution
1. Step 1
  Axes (Knowledge). Output (units) on the horizontal axis, costs/revenue (£) on the vertical axis, both labelled.
2. Step 2
  Fixed cost line (Application). A HORIZONTAL line at £10,000 (it doesn't change with output).
3. Step 3
  Total cost & revenue lines (Application). Total cost starts at £10,000 (at zero output) and slopes up; total revenue starts at the origin and slopes up more steeply.
4. Step 4
  Break-even point (Analysis). Where TR crosses TC — at 5,000 units (£20,000). Label the BEP and drop a line to the output axis.
Answer
Labelled axes; horizontal FC line at £10,000; TC from £10,000 sloping up; TR from origin, steeper; BEP where they cross (5,000 units), labelled.
Examiner tip
Full marks need labelled axes, the FC line HORIZONTAL, TC starting at FC, TR from the origin, and a labelled BEP. The most-penalised error is a sloping fixed-cost line.
6Analyse a negative margin of safety
StretchWord problem• WBS12 Section B style — Analyse (6 marks: Knowledge 2, Application 2, Analysis 2)• margin of safety, AO2, AO3
Question
BrewCo's break-even output is 12,000 units but it is currently selling only 9,000 units. Analyse the implications of this for BrewCo. (6 marks)
Step-by-step solution
1. Step 1
  Identify the problem (Knowledge + Application). Selling 9,000 against a break-even of 12,000 gives a NEGATIVE margin of safety of 3,000 units — BrewCo is below break-even.
2. Step 2
  Develop the chain (Analysis). Below break-even, BrewCo's contribution does not cover its fixed costs, so it is making a LOSS.
3. Step 3
  Extend the chain (Analysis). Ongoing losses mean cash outflows exceed inflows, so BrewCo may run short of cash, need emergency finance, and — if it can't raise sales or cut costs — risk business failure. It must act: raise sales, cut fixed costs, or raise contribution.
Answer
A negative margin of safety (−3,000 units) means BrewCo is below break-even and making a loss → cash outflows exceed inflows → may need finance → risk of failure unless it raises sales or cuts costs.
Examiner tip
6/6: develops the full chain from a negative margin of safety → loss → cash problem → risk of failure, applied to BrewCo. This is the signature 'implications of a negative margin of safety' question.

Model Answers — Break-even

High-scoring sample answers for break-even on the Cambridge IGCSE paper, with examiner-style notes mapping each response to the mark scheme and assessment objectives.

Question 1
WBS12 Section A style — Define (2 marks, Knowledge 2)2 marks
[Easy · 2 marks · Section A] Define the term 'contribution'.
Model answer
Contribution (per unit) is the selling price minus the variable cost per unit (1) — the amount each unit sold contributes towards paying fixed costs and then profit (1).
Why this scores
Knowledge 2: 'selling price − variable cost per unit' (1) plus 'contributes to fixed costs/profit' (1). Defining it as profit caps at 1.
Question 2
WBS12 Section A style — Calculate (4 marks: Knowledge 1, Application 2, Analysis 1)4 marks
[Easy · 4 marks · Section A] DeviceCo has fixed costs of £30,000, sells at £12 per unit with variable costs of £6 per unit, and currently sells 8,000 units. Calculate its break-even output AND its margin of safety. (4 marks)
Model answer
Contribution = £12 − £6 = £6 per unit (Knowledge 1). Break-even output = fixed costs ÷ contribution = £30,000 ÷ £6 = 5,000 units (Application 2). Margin of safety = actual − break-even = 8,000 − 5,000 = 3,000 units (Analysis 1).
Why this scores
4/4: contribution formula (Knowledge 1); break-even calculated correctly (Application 2); margin of safety with units (Analysis 1). Show each step; method marks apply if a figure slips.
Question 3
WBS12 Section B style — Analyse (6 marks: Knowledge 2, Application 2, Analysis 2)6 marks
[Medium · 6 marks · Section A] BrewCo's break-even output is 12,000 units but it is currently selling only 9,000 units. Analyse the implications of this for BrewCo. (6 marks)
Model answer
Selling 9,000 units against a break-even of 12,000 gives BrewCo a negative margin of safety of 3,000 units — it is operating below break-even (Knowledge + Application). This means BrewCo's total contribution does not cover its fixed costs, so it is currently making a loss on its operations (Analysis).

Sustained, this is serious: ongoing losses mean BrewCo's cash outflows exceed its inflows, so it may run short of cash and need emergency finance to keep trading (Knowledge + Application). If BrewCo cannot raise sales above 12,000 units, cut its fixed costs (lowering break-even), or increase contribution (raise price or cut variable cost), it risks business failure (Analysis).
Why this scores
6/6: develops the full chain — negative margin of safety → below break-even → loss → cash outflow exceeds inflow → needs finance → risk of failure — applied to BrewCo, plus the remedies. This is the signature negative-margin question; a partial chain caps the marks.
Question 4
WBS12 Section B style — Discuss (8 marks, 3-Level grid; Level 3 = 6–8)8 marks
[Medium · 8 marks · Section B] StartBrew, a start-up, has calculated a high break-even output and a small margin of safety. Discuss the significance of this for StartBrew. (8 marks)
Model answer
A high break-even output and a small margin of safety are a significant warning for StartBrew. A high break-even means it must sell a large volume of its brew just to cover its fixed brewing overheads — plant, rent and depreciation on its tanks — and a small margin of safety means it is only just above break-even, so even a small fall in sales would push StartBrew into a loss. For a start-up with uncertain, unproven demand, this is a risky, fragile position.

However, the significance depends on context. If StartBrew is in a growing market and expects sales to rise, its margin of safety should widen as output grows, so the current position may be a temporary start-up phase. The figures also rest on break-even's assumptions (constant price and costs, all output sold), which may not hold — unsold batches would not clear as the model assumes — so the exact numbers are uncertain. And StartBrew can act to improve the position — cutting fixed costs (lowering break-even), raising contribution per unit (higher price or lower variable cost through cheaper ingredient sourcing), or lifting sales volume.

On balance, the high break-even and small margin of safety are significant because they show StartBrew is vulnerable to any dip in sales — a real risk for an unproven start-up. But how serious this is depends on its growth prospects and ability to raise the margin of safety. StartBrew should treat the figures as a prompt to act — reducing fixed overheads and building sales volume to widen its safety margin — rather than as a fixed verdict, since improving contribution per unit or cutting fixed costs would quickly make its position safer.
Why this scores
Level 3 (6–8): weighs the risk shown by a small margin of safety against StartBrew's growth prospects and ability to improve it, with the evaluation embedded and break-even's assumptions noted. No separate conclusion needed at 8 marks.
Question 5
WBS12 Section A/B style — Assess (10 marks, 4-Level grid; Level 4 = 8–10)10 marks
[Hard · 10 marks · Section A/B] PlanBrew is using break-even analysis to plan a new product launch. Assess how useful break-even analysis is to PlanBrew for this decision. (10 marks)
Model answer
Break-even analysis is a natural tool for planning a launch, and PlanBrew relies on it — but its usefulness depends on how far its assumptions fit the launch.

Why break-even is useful. It tells PlanBrew the minimum sales volume needed to cover the new brew's fixed and variable costs (the break-even output) — a clear, concrete production target. It shows the margin of safety (how far sales can fall before a loss), helping PlanBrew assess risk, and it supports 'what-if' analysis — modelling how a different price or unit variable cost would move the break-even point. It is also simple and persuasive for a finance application. For a launch decision, this insight into targets and risk is genuinely valuable.

Its limits. However, break-even rests on simplifying assumptions that may not hold for a launch. It assumes a constant price (but PlanBrew may use introductory discounts or price skimming), constant unit costs (but bulk-buying discounts on ingredients and rising input prices change costs with output), and that all output is sold (uncertain for a new brew that could leave unsold batches). Its figures are only as good as PlanBrew's cost and sales estimates, which for a launch are unproven. And it is a static snapshot in a market that may change.

Judgement. On balance, break-even analysis is useful but not sufficient for PlanBrew's launch decision. It provides a valuable target and risk framework — the minimum sales volume and the margin of safety — that PlanBrew should certainly calculate. But because its assumptions (constant price/costs, all output sold) are shaky for a new product, PlanBrew should treat the results as indicative, not precise, combine them with market research on likely demand, and test different scenarios. So break-even is a useful starting point for the launch decision, most reliable when its assumptions roughly hold — but PlanBrew should not base the decision on it alone.
Why this scores
Level 4 (8–10): weighs break-even's usefulness (targets, risk, what-if) against its assumptions' weakness for a launch, applied to PlanBrew, with a judgement that it is a useful starting point but not sufficient. The 10-mark Assess is a 4-Level grid anchored to the named business; identifying WHICH assumptions fail for a launch (constant price, all output sold) is the AO4 discriminator.
Question 6
WBS12 Section C style — Evaluate (20 marks, 4-Level grid; Level 4 = 16–20)20 marks
[Hard · 20 marks · Section C] FoodCo, a manufacturer, relies heavily on break-even analysis in its financial planning. Evaluate the usefulness of break-even analysis to a business like FoodCo. (20 marks)
Model answer
Break-even analysis is a core financial-planning tool, and FoodCo relies on it — but it is a simplification, so its usefulness depends on how well its assumptions fit FoodCo's production operation and how it is used alongside other tools.

Why break-even is useful. It gives FoodCo the minimum output needed to avoid a loss (break-even output) — a clear target for its production lines and sales. It measures risk through the margin of safety, showing how far sales can fall before a loss, which helps FoodCo judge the safety of a product line or investment decision. It enables 'what-if' analysis — modelling how a price change, ingredient-cost change or investment in new plant would move the break-even point — supporting decisions. And it is simple, quick and persuasive, useful for setting targets and for finance applications. For routine planning and quick decisions, break-even is a genuinely valuable, accessible tool.

Its limitations. However, break-even rests on unrealistic assumptions. It assumes a constant selling price — but FoodCo may offer bulk-order discounts to retailers, so at high volumes the revenue line would bend, meaning simple break-even overstates revenue and profit. It assumes constant unit costs — but unit production costs change with output (economies of scale as capacity utilisation rises, or rising raw-material input prices). It assumes all output is sold, which is rarely true for perishable stock. It handles only a single product simply, whereas FoodCo likely runs many product lines. And it is a static snapshot in a market that changes, so the figures date. Its results are also only as reliable as FoodCo's cost and sales estimates.

Evaluation. How useful break-even is depends on context. It depends on how far its assumptions hold for FoodCo — if FoodCo relies heavily on trade discounting or has strongly changing input costs, simple break-even is less reliable; if its price and unit costs are fairly stable, it is more so. It depends on the decision — break-even is well-suited to quick target-setting and simple what-if analysis, less so to complex, multi-line or long-term strategic decisions. And it depends on how FoodCo uses it — as an indicative guide combined with market research and judgement, or (mistakenly) as a precise prediction.

Conclusion. On balance, break-even analysis is a useful but limited tool for FoodCo. It is genuinely valuable for setting output targets, assessing risk via the margin of safety, and quick what-if analysis — so FoodCo is right to use it in its planning. But because its assumptions (constant price/costs, all output sold, single product) often don't fully hold for a real food manufacturer, FoodCo should treat break-even as an indicative guide, not a precise forecast, use realistic estimates, and combine it with market research and other financial tools. Its usefulness is greatest for simple, short-term planning where its assumptions roughly hold, and least for complex or discount-driven decisions. So FoodCo should keep using break-even — but as one tool among several, aware of its simplifying assumptions.
Why this scores
Level 4 (16–20): weighs break-even's usefulness (targets, risk, what-if, simplicity) against its assumptions (constant price/costs, all output sold, single product, static), applied to FoodCo, and reaches an evaluative 'useful but limited — an indicative guide' conclusion conditional on how far assumptions hold and how it's used. The 20-mark Evaluate is a 4-Level grid anchored to the named business; identifying which assumptions fail (esp. constant price vs discounting) is the AO4 discriminator.

Key Formulae — Break-even

The formulae you need to memorise for break-even on the Cambridge IGCSE paper, with every variable defined in plain English and a note on when to use it.

Contribution per unit
$\text{Contribution per unit} = \text{selling price} - \text{variable cost per unit}$
$\text{selling price}$
the price charged per unit
$\text{variable cost per unit}$
the variable cost of producing one unit
When to use
To find what each unit contributes to fixed costs and then profit. The basis of the break-even formula.
Example
£4 − £2 = £2 per unit.
Break-even output
$\text{Break-even output} = \frac{\text{fixed costs}}{\text{contribution per unit}}$
$\text{fixed costs}$
total fixed costs
$\text{contribution per unit}$
selling price − variable cost per unit
When to use
To find the output at which total revenue equals total costs (no profit, no loss).
Example
£10,000 ÷ £2 = 5,000 units.
Margin of safety
$\text{Margin of safety} = \text{actual output} - \text{break-even output}$
$\text{actual output}$
the current or planned level of sales
$\text{break-even output}$
the break-even level of output
When to use
To find how far sales can fall before the firm makes a loss. Negative = already making a loss.
Example
8,000 − 5,000 = 3,000 units.
Profit (from contribution)
$\text{Profit} = (\text{contribution per unit} \times \text{units sold}) - \text{fixed costs}$
$\text{contribution per unit}$
selling price − variable cost per unit
$\text{units sold}$
the number of units sold
$\text{fixed costs}$
total fixed costs
When to use
To find profit once contribution and fixed costs are known (total contribution minus fixed costs).
Example
(£2 × 8,000) − £10,000 = £6,000.

Key Definitions and Keywords — Break-even

Definitions to memorise and the exact keywords mark schemes credit for break-even answers — sharpened from recent examiner reports for the 2026 Cambridge IGCSE sitting.

Contribution per unit
Examiner keyword
The amount each unit sold contributes towards fixed costs and then profit, equal to selling price − variable cost per unit.
Break-even output
Examiner keyword
The level of output at which total revenue exactly equals total costs, so the business makes neither a profit nor a loss.
Margin of safety
Examiner keyword
The amount by which actual output exceeds the break-even output — how far sales can fall before a loss.
Break-even chart
Examiner keyword
A graph plotting fixed costs, total costs and total revenue against output, showing the break-even point where total revenue crosses total cost.
Total contribution
Examiner keyword
Contribution per unit multiplied by the number of units sold.
Fixed cost line
Examiner keyword
A horizontal line on a break-even chart, at the fixed-cost value, because fixed costs do not change with output.

Common Mistakes and Misconceptions — Break-even

The traps other students keep falling into on break-even questions — taken from recent Cambridge IGCSE examiner reports and mark schemes — and how to avoid them.

✕Drawing the fixed-cost line sloping upward on the break-even chart
WBS12 Examiner Reports
Why it happens
Students draw all cost lines rising.
How to avoid it
Fixed costs are HORIZONTAL (they don't change with output). The TOTAL cost line slopes up, starting at the fixed-cost value. This is the most-penalised chart error.
✕Dividing by the wrong figure in the break-even formula
Why it happens
Students divide by price or total variable cost.
How to avoid it
Break-even output = fixed costs ÷ contribution PER UNIT. Not price, not total variable cost.
✕Confusing contribution with profit
Why it happens
Both are 'money made per unit'.
How to avoid it
Contribution per unit ignores fixed costs; profit = total contribution MINUS fixed costs.
✕Ignoring a negative margin of safety
Why it happens
Students expect a positive number.
How to avoid it
A negative margin of safety means output is BELOW break-even — the firm is making a LOSS, a serious warning.
✕Treating break-even as certain, ignoring its assumptions
Why it happens
The chart looks precise.
How to avoid it
Break-even assumes constant price and costs and that all output is sold — flag these limitations in evaluation.
✕Answering a 6-mark 'Analyse two…' question with only one point
WBS12 mark schemes
Why it happens
Students develop the first point and forget the command needs two.
How to avoid it
6-mark Analyse = Knowledge 2, Application 2, Analysis 2 — give TWO points, each developed (2+2+2).

Break-even

Detailed Study Notes

At a glance

What you’ll learn

Quick recap

Memorise this

How it’s examined

Take this whole topic with you

1Calculate contribution per unit

2Calculate break-even output

3Calculate the margin of safety

4Calculate profit using contribution

5Construct a break-even chart

6Analyse a negative margin of safety

Contribution per unit

Break-even output

Margin of safety

Profit (from contribution)

Contribution per unit

Break-even output

Margin of safety

Break-even chart

Total contribution

Fixed cost line

✕Drawing the fixed-cost line sloping upward on the break-even chart

✕Dividing by the wrong figure in the break-even formula

✕Confusing contribution with profit

✕Ignoring a negative margin of safety

✕Treating break-even as certain, ignoring its assumptions

✕Answering a 6-mark 'Analyse two…' question with only one point