AQA A-Level Accounting (7127)

## Learning Outcomes

- Define **marginal costing** and explain why contribution is central to it
- Calculate **contribution per unit** and **total contribution** accurately
- Distinguish clearly between **contribution** and **profit**
- Prepare and interpret a simple **marginal costing statement**
- Apply contribution figures to related tasks such as profit and break-even
- Avoid common exam errors in contribution calculations

## AQA A-Level Accounting (7127) Syllabus

For the AQA A-Level Accounting (7127), you are expected to understand contribution within marginal costing, with a focus on the following syllabus points:

- Know that **contribution per unit = selling price per unit − variable cost per unit**
- Know that **total contribution = total sales revenue − total variable costs**
- Identify that total contribution can also be found by **contribution per unit × units sold**
- Explain that contribution is used **first to cover fixed costs** and only then to create profit
- Understand that **profit = total contribution − fixed costs**
- Distinguish between **variable costs** and **fixed costs** in marginal costing
- Apply contribution figures in marginal costing statements and linked exam calculations
- Explain why contribution is more useful than total cost for short-term decision-making

## Test Your Knowledge

_Attempt these questions before reading this article. If you find some difficult or cannot remember the answers, look more closely at that area during your revision._

1. What is the formula for contribution per unit?
2. How is total contribution different from profit?
3. A product sells for £18 and has variable costs of £11 per unit. What is the contribution per unit?
4. How can total contribution be calculated in two different ways?
5. Why are fixed costs not included when calculating contribution per unit?

## Introduction

Contribution is one of the most tested ideas in marginal costing because it links directly to profit, break-even, target profit and short-term decisions. If you can calculate contribution quickly and explain what it means, you are building the foundation for a large part of Paper 2.

Under marginal costing, the focus is on how much each unit sold contributes towards the fixed costs of the business and, after those are covered, towards profit. This is why students must not treat contribution as just another formula to memorise. You need to understand what the figure means in context.

> **Key Term: marginal costing**
> A costing technique that focuses on variable costs and the cost of producing one extra unit of output.

## Introduction to contribution in marginal costing

Contribution sits between sales revenue and profit. A business receives sales revenue, pays variable costs, and the amount left is contribution. That contribution is then used to cover fixed costs. If there is anything left after fixed costs have been covered, that remainder is profit.

> **Key Term: contribution**
> The amount remaining after variable costs have been deducted from sales revenue.

This gives the core relationship:

$$
\text{sales revenue} - \text{variable costs} = \text{contribution}
$$

Then:

$$
\text{contribution} - \text{fixed costs} = \text{profit}
$$

A very useful memory chain is:

- **Sales**
- less **variable costs**
- equals **contribution**
- less **fixed costs**
- equals **profit**

Students often understand the arithmetic but miss the meaning. Contribution is not the final gain for the business. It is the amount available to meet fixed costs first.

> **Key Term: variable costs**
> Costs that vary in total in proportion to output or activity.

Common variable costs in marginal costing questions include:

- direct materials
- direct labour
- variable production overheads
- the variable element of semi-variable costs

Fixed costs are treated differently. They are costs of time rather than output, so they are not included in contribution per unit.

> **Key Term: fixed costs**
> Costs that do not normally change with the level of output over a given range of activity.
>
> **Test Tip:** In calculation questions, write the formula first. AQA often rewards method as well as the final answer, and clear workings reduce avoidable mistakes.

### Contribution per unit

Contribution per unit shows how much one unit sold adds towards fixed costs and profit.

The formula is:

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

Suppose a business sells a product for **£24** per unit. Variable costs per unit are:

- direct materials: **£7**
- direct labour: **£5**
- variable overheads: **£3**

Step 1: calculate total variable cost per unit

$$
£7 + £5 + £3 = £15
$$

Step 2: calculate contribution per unit

$$
£24 - £15 = £9
$$

So the contribution per unit is **£9**.

This means each unit sold provides **£9** towards fixed costs first, and then profit.

A side-by-side reminder helps:

| Figure                 | Meaning                                             |
| ---------------------- | --------------------------------------------------- |
| Selling price per unit | What the customer pays per unit                     |
| Variable cost per unit | The extra cost of making one unit                   |
| Contribution per unit  | The amount left from each unit after variable costs |

Students often confuse contribution per unit with profit per unit. They are not the same. If fixed costs still need to be covered, the business may have a positive contribution per unit but still make an overall loss.

Worked example:

A product sells for **£10** per unit and variable cost is **£6** per unit.

$$
\text{Contribution per unit} = £10 - £6 = £4
$$

If fixed costs are **£5,000**, the business does not make **£4 profit** on each unit. It makes **£4 contribution** on each unit. Profit only starts after enough units have been sold to cover the **£5,000** fixed costs.

Common student errors with contribution per unit:

- including fixed costs in the variable cost per unit
- subtracting total cost instead of variable cost
- calling contribution per unit “profit per unit”
  > **Key Term: contribution per unit**
  > The amount each unit sold contributes towards fixed costs and profit, found by subtracting variable cost per unit from selling price per unit.

### Total contribution

Total contribution measures the contribution made by all units sold in a period.

There are two valid methods:

$$
\text{total contribution} = \text{total sales revenue} - \text{total variable costs}
$$

or

$$
\text{total contribution} = \text{contribution per unit} \times \text{number of units sold}
$$

Both methods should give the same answer.

Worked example 1: using totals

A business sells **2,500 units** at **£18** each.

Total sales revenue:

$$
2,500 \times £18 = £45,000
$$

Variable cost per unit is **£11**, so total variable costs are:

$$
2,500 \times £11 = £27,500
$$

Total contribution:

$$
£45,000 - £27,500 = £17,500
$$

Worked example 2: using contribution per unit

Contribution per unit:

$$
£18 - £11 = £7
$$

Total contribution:

$$
2,500 \times £7 = £17,500
$$

Same result, as expected.

This is a common AQA move: one part of the question asks for contribution per unit, and the next asks for total contribution or profit. You should carry your earlier figure forward carefully.

A useful check is this: if the contribution per unit is positive, total contribution should rise as more units are sold, assuming selling price and variable cost per unit stay unchanged.

> **Key Term: total contribution**
> The contribution made by all units sold in a period, found from total sales revenue minus total variable costs, or contribution per unit multiplied by units sold.

Worked example with a marginal costing statement:

A business sells **1,000 units** at **£35** each. Variable costs are:

- direct materials: **£7,500**
- direct labour: **£10,500**
- variable overheads: **£6,000**
- variable element of semi-variable cost: **£1,500**

Fixed costs are **£3,000**.

Step 1: total sales revenue

$$
1,000 \times £35 = £35,000
$$

Step 2: total variable costs

$$
£7,500 + £10,500 + £6,000 + £1,500 = £25,500
$$

Step 3: total contribution

$$
£35,000 - £25,500 = £9,500
$$

Step 4: profit

$$
£9,500 - £3,000 = £6,500
$$

Marginal costing statement:

|                     |      £ |
| ------------------- | -----: |
| Sales revenue       | 35,000 |
| Less variable costs | 25,500 |
| Contribution        |  9,500 |
| Less fixed costs    |  3,000 |
| Profit              |  6,500 |

This format is worth learning exactly.

> **Test Tip:** Label each stage clearly: sales revenue, variable costs, contribution, fixed costs, profit. Clear labels make it easier for the examiner to award marks, especially in longer calculations.

### Contribution, fixed costs and profit

The most important interpretation point is that contribution covers fixed costs before profit is made.

A business can have:

- positive contribution
- but no profit
- or even an overall loss

Example:

A product has contribution per unit of **£5**. The business sells **800 units**. Fixed costs are **£5,000**.

Total contribution:

$$
800 \times £5 = £4,000
$$

Profit:

$$
£4,000 - £5,000 = (£1,000)
$$

So the business makes a **loss of £1,000**, even though every unit sold gave a positive contribution.

This is why contribution is useful for short-run decisions. If a special order creates extra positive contribution and fixed costs do not change, profits increase. But contribution itself is still not profit.

At break-even:

$$
\text{total contribution} = \text{fixed costs}
$$

and therefore:

$$
\text{profit} = £0
$$

That link makes contribution a starting point for later topics such as break-even and target profit.

A quick comparison:

| Term         | Meaning                               |
| ------------ | ------------------------------------- |
| Contribution | Sales less variable costs             |
| Profit       | Contribution less fixed costs         |
| Break-even   | Total contribution equals fixed costs |

Common student errors in this area:

- saying contribution is “the same as profit”
- forgetting to deduct fixed costs after finding total contribution
- using contribution per unit where total contribution is needed, or vice versa

### How to structure an evaluative answer

When a longer written response uses contribution, do not stop at the arithmetic. Start with the calculation, then explain what it shows.

A good evaluative structure is:

- state the contribution figure clearly
- explain whether it helps cover fixed costs and by how much
- comment on the effect on overall profit
- mention key assumptions or limits if relevant

Financial evidence to cite:

- contribution per unit
- total contribution
- fixed costs
- resulting profit or loss

Non-financial points to discuss if the question asks for advice:

- spare capacity
- likely effect on existing customers
- quality issues
- reliability of sales estimates

Avoid vague limitations. Be specific. For example, do not just say “there may be other factors”. Say “the order may bring positive contribution, but if it disrupts normal production the financial gain may not be achieved”.

## Key Point Checklist

_This article has covered the following key knowledge points:_

- Marginal costing focuses on variable costs and the cost of producing one extra unit
- Contribution is sales revenue minus variable costs
- Contribution per unit equals selling price per unit minus variable cost per unit
- Total contribution equals total sales revenue minus total variable costs
- Total contribution can also be calculated as contribution per unit multiplied by units sold
- Contribution is not the same as profit
- Contribution is used first to cover fixed costs
- Profit is calculated as total contribution minus fixed costs
- A business can make positive contribution but still make an overall loss
- A marginal costing statement shows sales, variable costs, contribution, fixed costs and profit
- Fixed costs must not be included in contribution per unit
- Contribution is a key starting figure for break-even, target profit and short-term decisions

## Key Terms and Concepts

- marginal costing
- contribution
- variable costs
- fixed costs
- contribution per unit
- total contribution


Marginal costing - Contribution (total and per unit)