What it means
When a factory makes a product, some costs rise with every extra unit, such as raw materials, hourly labour and power to run the machines. Others stay the same whether the factory makes one unit or ten thousand, such as rent, insurance, salaried managers and depreciation on equipment.
Absorption costing says that all of these are costs of making the product, so all of them should be attached to the units produced. The practical effect is that fixed manufacturing overhead is spread across the units made in the period.
Each unit carries a slice of it. When the unit is sold, that slice moves into cost of goods sold, and when the unit sits in inventory at year end, the slice sits on the balance sheet as part of inventory value rather than hitting the income statement.
This is the key difference from variable costing, where fixed manufacturing overhead is treated as a period expense and charged to the income statement immediately, regardless of what was sold. Under absorption costing, producing more units than you sell pushes some fixed cost into inventory and makes reported profit higher for that period.
Producing fewer units than you sell does the opposite. Accounting standards require absorption costing for published accounts because they take the view that fixed factory costs are a real part of the cost of creating inventory.
Internally, many managers prefer variable costing for decision making because it does not let production volume distort profit. For a non-finance manager, the practical lesson is to ask what production volume sits behind a profit figure.
Two businesses with identical sales can report very different profits simply because one built stock and the other did not. Think of absorption costing as splitting a restaurant's rent across every meal served, not just the ingredients.
Each unit absorbs its share of everything it took to run the kitchen.
In practice
Real-world examples
Example 1
A bakery that rents its premises includes a share of the rent in the cost of each loaf on its balance sheet, not just flour, yeast and the baker's wages. If the bakery bakes 20,000 loaves in a month and rent is $4,000, each loaf carries $0.20 of rent. The cost per loaf is higher than the ingredients alone would suggest.
Example 2
A car plant running below capacity spreads the same fixed costs over fewer cars, so the recorded cost per car rises even though nothing about the car changed. Management has to decide whether to cut the price to fill capacity or accept a thinner margin. Either way, the accounts show the cost increase as soon as the cars are sold.
Example 3
A manager judged on absorption-cost profit has an incentive to overproduce at year end, because building inventory parks fixed overhead on the balance sheet and lifts reported profit. The extra stock may be unwanted and costly to store. A sensible finance team watches inventory levels alongside profit to spot this pattern.
Think of it
Absorption costing loads all factory costs onto products-each unit absorbs its share of everything.
Formula
Calculation
Unit product cost = Direct Materials + Direct Labour + Variable Manufacturing Overhead + (Fixed Manufacturing Overhead / Units Produced)
Worked example. A furniture workshop produces 10,000 chairs in a year:
- Direct materials per chair: $20
- Direct labour per chair: $15
- Variable manufacturing overhead per chair: $5
- Total fixed manufacturing overhead for the year: $100,000
Fixed overhead per chair = $100,000 / 10,000 = $10
Unit product cost = $20 + $15 + $5 + $10 = $50 per chair
If the workshop sells 8,000 chairs at $80 each:
- Revenue = 8,000 x $80 = $640,000
- Cost of goods sold = 8,000 x $50 = $400,000
- Gross profit = $640,000 - $400,000 = $240,000
The 2,000 unsold chairs are carried in inventory at $50 each, or $100,000. That includes $20,000 of fixed overhead (2,000 x $10) that has been deferred to a future period rather than expensed this year. Under variable costing, all $100,000 of fixed overhead would be expensed now, so profit would be $20,000 lower, at $220,000.Case study
Seen in the real world
This is a fictional, illustrative scenario. A mid-sized garden tool maker had a weak sales year but kept its production line running at full capacity to "keep the team busy". Under absorption costing, the extra 30,000 units of unsold inventory absorbed $450,000 of fixed overhead, which is $15 a unit, and reported operating profit came in only slightly below the prior year. The following year, sales stayed flat, the company cut production to run down inventory, and that deferred $450,000 of overhead flowed through cost of goods sold.
Profit collapsed, even though the underlying business had not changed between the two years. The board learned to read variable-costing reports alongside the statutory accounts. The finance director also changed the bonus plan so that managers were no longer rewarded on reported profit alone. Targets now include inventory days and cash generated, which removed the temptation to build stock for the sake of the numbers.
Watch out
Common mistakes
- Assuming higher production means the product got cheaper to make. Under absorption costing the unit cost falls with volume purely because fixed overhead is spread more thinly.
- Using absorption cost per unit for a one-off pricing decision. For a special order that uses spare capacity, only the variable cost is relevant.
- Ignoring the inventory build-up when comparing profit between periods. A rise in profit may simply reflect more fixed overhead parked on the balance sheet.
Questions
People also ask
Is absorption costing the same as full costing?
Yes, the terms are used interchangeably.
Which method gives higher profit?
When production exceeds sales, absorption costing reports higher profit. When sales exceed production, variable costing reports higher profit. When they are equal, both agree.
Do service businesses use absorption costing?
Rarely in the strict sense, because they hold little or no inventory, but the principle of allocating overhead to jobs or clients is similar.
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