Management Accounting · Absorption and marginal costing

Absorption vs Marginal Costing Profit Reconciliation for ACCA MA

Q: Why does absorption costing give higher profit when production exceeds sales?

Some fixed production overhead is included in the value of unsold units. It is carried forward in inventory instead of being charged this period. So less cost is deducted and profit is higher.

Q: Do the two methods ever give the same profit?

Yes. If opening and closing inventory units are equal, the same fixed overhead is charged under both methods. Total profit across the product's whole life is also the same.

Q: Which costs cause the profit difference?

Only fixed production overhead. Variable costs are treated the same way in both methods. Selling and administration costs are period costs in both.

Q: How do I reconcile the two profits in the exam?

Find the inventory change in units and multiply it by the fixed overhead per unit. Then add or subtract the result from the profit you know, using the direction of the inventory change.

Updated 11 October 2026 · Fact-checked

Absorption costing carries fixed production overhead in inventory; marginal costing writes it off in the period. So profits differ when inventory changes. Reconcile by multiplying the change in inventory units by the fixed overhead absorbed per unit. Inventory up: absorption profit is higher. Inventory down: marginal profit is higher.

Understand Absorption vs Marginal Costing Profit Reconciliation

Both methods value sold units at the same variable cost. They differ only in how they treat fixed production overhead.

Under marginal costing, inventory is valued at variable production cost only. All fixed production overhead is charged to the period as a cost. Under absorption costing, inventory is valued at full production cost, which includes a share of fixed production overhead. That share is carried forward in closing inventory and only charged when the units are sold.

So when inventory goes up (production exceeds sales), some fixed overhead is held back in inventory under absorption costing. Less cost hits the income statement, so absorption profit is higher than marginal profit. When inventory goes down (sales exceed production), earlier overhead held in opening inventory is released. More cost hits the income statement, so absorption profit is lower than marginal profit.

If inventory does not change, both methods give the same profit. Over the whole life of a product, total profit is the same too. The difference is only one of timing.

Only fixed production overhead matters here. Selling, distribution and administration costs are period costs under both methods, so they never cause a difference.

Key formulas to remember

Profit difference: Absorption profit − Marginal profit = (Closing inventory units − Opening inventory units) × Fixed overhead absorption rate per unit; A positive answer means absorption profit is higher. A negative answer means marginal profit is higher.
Fixed overhead absorption rate per unit: Budgeted fixed production overhead ÷ Budgeted production units; Use the rate absorbed in the period. If the rate is per labour hour, convert it to a rate per unit first.
Inventory rule: Inventory up: absorption profit > marginal profit. Inventory down: absorption profit < marginal profit. No change: profits equal.; Holds when the fixed overhead rate per unit is the same in both periods.
Inventory value: Marginal: variable production cost per unit. Absorption: variable production cost + fixed production overhead per unit; Do not include selling or administration costs in inventory under either method.

How to solve Absorption vs Marginal Costing Profit Reconciliation questions

Use this method for any question asking why the profits differ or asking you to reconcile them.

1Find the opening and closing inventory in units. If not given, use opening inventory + production − sales.
2Work out the change in inventory in units. Note whether it is an increase or a decrease.
3Find the fixed production overhead absorbed per unit. Divide budgeted fixed production overhead by budgeted output.
4Multiply the change in inventory units by the rate per unit. This is the profit difference.
5Decide the direction. Increase means absorption profit is higher. Decrease means marginal profit is higher.
6Start from the profit you know. Add or subtract the difference to reach the other profit.
7Check: the difference should equal the fixed overhead in closing inventory minus the fixed overhead in opening inventory.

Quickest way: Units change × rate

When to use it: Use this for multiple-choice and number-entry questions where you only need the profit difference or the other profit figure.

Write production and sales units. Production minus sales is the inventory change.
Multiply that change by the fixed overhead rate per unit.
If production is higher than sales, add the amount to marginal profit to get absorption profit.
If sales are higher than production, subtract the amount from marginal profit to get absorption profit.
Ignore selling and administration costs and variable costs. They are the same in both methods.

Common mistakes in Absorption vs Marginal Costing Profit Reconciliation

Using the wrong direction for the adjustment.
Students memorise a rule without understanding that inventory carries overhead forward.
Fix: Ask: did overhead get stored or released? Inventory up means stored, so absorption profit is higher.
Multiplying by total inventory instead of the change in inventory.
Students value closing inventory and forget the opening inventory adjustment.
Fix: Use closing units minus opening units. Only the movement affects the profit difference.
Including variable cost or selling cost in the rate.
Students use total cost per unit instead of the fixed production overhead only.
Fix: Use only fixed production overhead per unit. Variable cost is the same in both methods.
Using the wrong number of units for the rate.
Students divide by sales units instead of budgeted production units.
Fix: The absorption rate is based on budgeted production (or activity). Check the question wording.
Forgetting that over- or under-absorption exists.
Actual production differs from budget, but students ignore the adjustment.
Fix: Read the question for under- or over-absorbed overhead. The reconciliation by inventory movement uses the rate; any other adjustment is separate.

Worked examples

Example 1

A company budgets fixed production overhead of $120,000 and production of 20,000 units. In the month, it produced 5,000 units and sold 4,200 units. There was no opening inventory. Marginal costing profit was $38,000. Assume actual fixed overhead equals the amount absorbed. Calculate the absorption costing profit.

Show the solution

Fixed overhead rate = $120,000 ÷ 20,000 = $6 per unit.
Inventory change = 5,000 − 4,200 = 800 units increase.
Profit difference = 800 × $6 = $4,800.
Inventory increased, so absorption profit is higher.
Absorption profit = $38,000 + $4,800 = $42,800.

Answer: Absorption costing profit is $42,800.

Example 2

Last month, opening inventory was 1,500 units and closing inventory was 900 units. The fixed production overhead absorption rate is $8 per unit. Absorption costing profit was $56,000. Calculate the marginal costing profit.

Show the solution

Inventory change = 900 − 1,500 = 600 units decrease.
Profit difference = 600 × $8 = $4,800.
Inventory fell, so overhead was released from opening inventory under absorption costing.
Absorption profit is lower than marginal profit by $4,800.
Marginal profit = $56,000 + $4,800 = $60,800.

Answer: Marginal costing profit is $60,800.

Exam tips

Check first whether inventory rose or fell. This tells you which profit is bigger before you calculate.
Read whether the rate is per unit or per hour. Convert to a unit rate before multiplying.
In multiple-response questions, a statement saying profits differ when there is no inventory change is false.
Do a quick sense check. If production exceeds sales and your absorption profit is lower, you have the direction wrong.

Practice questions from Absorption and marginal costing

Absorption vs Marginal Costing Profit Reconciliation in other exams

The same ground in other exams, if you are preparing for more than one or want another angle on it.

Absorption vs Marginal Costing Profit Reconciliation: frequently asked questions

Why does absorption costing give higher profit when production exceeds sales?

Some fixed production overhead is included in the value of unsold units. It is carried forward in inventory instead of being charged this period. So less cost is deducted and profit is higher.

Do the two methods ever give the same profit?

Yes. If opening and closing inventory units are equal, the same fixed overhead is charged under both methods. Total profit across the product's whole life is also the same.

Which costs cause the profit difference?

Only fixed production overhead. Variable costs are treated the same way in both methods. Selling and administration costs are period costs in both.

How do I reconcile the two profits in the exam?

Find the inventory change in units and multiply it by the fixed overhead per unit. Then add or subtract the result from the profit you know, using the direction of the inventory change.