Variable Costing:
A Tool for Management
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Beware of the Average Costs
•
•
Is the average cost a variable or fixed cost?
Recall that total costs include
 fixed costs that do not change with volume
 variable costs that do change with volume
AC = TC / q = (VC + FC) / q = v + FC / q
•
Decisions based on average costs may be
erroneous.
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Example: Vortex Inc.
• Vortec has contracted with customers to sell
100,000 units $5.00 per unit.
 Its total cost with this contract is estimated to be
$450,000, i.e., $4.50 per unit
• Vortec has a new business opportunity to sell
additional 2,000 units at $4 per unit.
 In that case, the estimated average cost is $4.47 for
the total 102,000 units.
• The additional sales do not affect the current
administrative expenses $27,500.
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Example: Vortex Inc.
• You are the owner of this company.
• You are concerned about the price of the
additional sales $4.00, which is lower than the
average unit cost $4.47.
 What will you do for this additional sales opportunity?
 Provide an analysis guiding your decision of whether
or not to sell the additional 2,000 units?
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Example: Vortex Inc.
• Units produced and sold
Total Revenue and Costs:
Sales ($5.00 regular,
$4.00 special)
Cost of sales ($4.50, $4.47)
Administrative expenses
Net profit before taxes
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Current Special Order
100,000
102,000
$ 500,000
450,000
- 27,500
$ 22,500
$508,000
455.940
- 27,500
$ 24,560
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Example: Vortex Inc.
Alternatively,
• Incremental revenue (2,000 units x $4.00)
• Incremental cost of 2,000 units
$8,000
 Total cost @ 102,000 units (102,000 x $4.47) 455,940
 Total cost @ 100,000 units (100,000 x $4.50) 450,000
• Incremental profit of 2,000 units
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5,940
$2,060
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Example: Vortex Inc.
• Is the average cost of $4.47 useful information?
• How much is the average cost per unit to produce
the additional 2,000 units?
 The incremental cost per unit of the 2000 units
$(455,940 – 450,000) / 2000
= $5940 / 2000
= $2.97 < 4.47
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Learning Objective 1
Explain how variable
costing differs from
absorption costing and
compute unit product
costs under each method.
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Overview of Absorption
and Variable Costing
Absorption
Costing
Variable
Costing
Direct Materials
Product
Costs
Product
Costs
Direct Labor
Variable Manufacturing Overhead
Fixed Manufacturing Overhead
Period
Costs
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Variable Selling and Administrative Expenses
Period
Costs
Fixed Selling and Administrative Expenses
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Quick Check 
Which method will produce the highest values for
work in process and finished goods inventories?
a. Absorption costing.
b. Variable costing.
c. They produce the same values for these
inventories.
d. It depends. . .
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Quick Check 
Which method will produce the highest values for
work in process and finished goods inventories?
a. Absorption costing.
b. Variable costing.
c. They produce the same values for these
inventories.
d. It depends. . .
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Unit Cost Computations
Harvey Company produces a single product
with the following information available:
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Unit Cost Computations
Unit product cost is determined as follows:
Under absorption and variable costing, selling
and administrative expenses are
always treated as period expenses and
deducted from revenue as incurred.
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Learning Objective 2
Prepare income
statements using both
variable and absorption
costing.
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Income Comparison of
Absorption and Variable Costing
Let’s assume the following additional
information for Harvey Company.
 20,000 units were sold during the year at a price of
$30 each.
 There were no units in beginning inventory.
Now, let’s compute net operating
income using both absorption
and variable costing.
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Absorption Costing
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Variable Costing
Variable
manufacturing
Variable Costing
costs only.
Sales (20,000 × $30)
Less variable expenses:
Beginning inventory
$
Add COGM (25,000 × $10)
250,000
Goods available for sale
250,000
Less ending inventory (5,000 × $10)
50,000
Variable cost of goods sold
200,000
Variable selling & administrative
expenses (20,000 × $3)
60,000
Contribution margin
Less fixed expenses:
Manufacturing overhead
$ 150,000
Selling & administrative expenses 100,000
Net operating income
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$ 600,000
All fixed
manufacturing
overhead is
expensed.
260,000
340,000
250,000
$ 90,000
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Learning Objective 3
Reconcile variable costing
and absorption costing net
operating incomes and
explain why the two
amounts differ.
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Comparing the Two Methods
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Comparing the Two Methods
We can reconcile the difference between
absorption and variable income as follows:
Variable costing net operating income
$ 90,000
Add: Fixed mfg. overhead costs
deferred in inventory
(5,000 units × $6 per unit)
30,000
Absorption costing net operating income $ 120,000
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Extended Comparisons of Income Data
Harvey Company Year Two
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Unit Cost Computations
Since there was no change in the variable costs
per unit, total fixed costs, or the number of
units produced, the unit costs remain unchanged.
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Absorption Costing
Absorption Costing
Sales (30,000 × $30)
Less cost of goods sold:
Beg. inventory (5,000 × $16)
Add COGM (25,000 × $16)
Goods available for sale
Less ending inventory
Gross margin
Less selling & admin. exp.
Variable (30,000 × $3)
Fixed
Net operating income
$ 900,000
$ 80,000
400,000
480,000
-
$ 90,000
100,000
480,000
420,000
190,000
$ 230,000
These are 25,000 units
produced in the current period.
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Variable Costing
Variable
manufacturing
costs only.
All fixed
manufacturing
overhead is
expensed.
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Comparing the Two Methods
We can reconcile the difference between
absorption and variable income as follows:
Variable costing net operating income
$ 260,000
Deduct: Fixed manufacturing overhead
costs released from inventory
(5,000 units × $6 per unit)
30,000
Absorption costing net operating income $ 230,000
Fixed mfg. Overhead
$150,000
=
= $6.00 per unit
Units produced
25,000 units
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Summary of Key Insights
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Effect of Changes in Production
on Net Operating Income
Let’s revise the Harvey Company example.
In the previous example,
25,000 units were produced each year,
but sales increased from 20,000 units in year
one to 30,000 units in year two.
In this revised example,
production will differ each year while
sales will remain constant.
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Effect of Changes in Production
Harvey Company Year One
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Unit Cost Computations for Year One
Unit product cost is determined as follows:
Since the number of units produced increased
in this example, while the fixed manufacturing overhead
remained the same, the absorption unit cost is less.
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Absorption Costing: Year One
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Variable Costing: Year One
Variable
manufacturing
Variable Costing
costs only.
Sales (25,000 × $30)
Less variable expenses:
Beginning inventory
$
Add COGM (30,000 × $10)
300,000
Goods available for sale
300,000
Less ending inventory (5,000 × $10)
50,000
Variable cost of goods sold
250,000
Variable selling & administrative
expenses (25,000 × $3)
75,000
Contribution margin
Less fixed expenses:
Manufacturing overhead
$ 150,000
Selling & administrative expenses 100,000
Net operating income
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$ 750,000
All fixed
manufacturing
overhead is
expensed.
325,000
425,000
250,000
$ 175,000
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Effect of Changes in Production
Harvey Company Year Two
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Unit Cost Computations for Year Two
Unit product cost is determined as follows:
Since the number of units produced decreased in the
second year, while the fixed manufacturing overhead
remained the same, the absorption unit cost is now higher.
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Absorption Costing: Year Two
Absorption Costing
Sales (25,000 × $30)
Less cost of goods sold:
Beg. inventory (5,000 × $15)
Add COGM (20,000 × $17.50)
Goods available for sale
Less ending inventory
Gross margin
Less selling & admin. exp.
Variable (25,000 × $3)
Fixed
Net operating income
$ 750,000
$ 75,000
350,000
425,000
-
$ 75,000
100,000
425,000
325,000
175,000
$ 150,000
These are the 20,000 units produced in the current
period at the higher unit cost of $17.50 each.
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Variable Costing: Year Two
Variable
manufacturing
costs only.
All fixed
manufacturing
overhead is
expensed.
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Comparing the Two Methods
Conclusions
 Net operating income is not affected by changes in
production using variable costing.
 Net operating income is affected by changes in production
using absorption costing even though the number of units
sold is the same each year.
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Learning Objective 4
Understand the
advantages and
disadvantages of both
variable and absorption
costing.
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Variable versus Absorption Costing
Fixed manufacturing
costs must be assigned
to products to properly
match revenues and
costs.
Absorption
Costing
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Fixed manufacturing
costs are capacity costs
and will be incurred
even if nothing is
produced.
Variable
Costing
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Impact on the Manager
Opponents of absorption costing argue that
shifting fixed manufacturing overhead costs
between periods can lead to faulty decisions.
These opponents argue that variable costing income
statements are easier to understand because net operating
income is only affected by changes in unit sales. This
produces net operating income figures that are
more consistent with managers’ expectations.
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CVP Analysis, Decision Making
and Absorption costing
Absorption costing does not support CVP
analysis because it essentially treats fixed
manufacturing overhead as if it is a variable cost
by assigning a per unit amount of the fixed
overhead to each unit of production.
Treating fixed manufacturing overhead as a
variable cost can:
• Lead to erroneous decisions.
• Example: Vortec Inc.
• Produce a positive net operating income even
when the number of units sold is less than the
breakeven point.
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Advantages of Variable Costing
and the Contribution Approach
Management finds
it more useful.
Consistent with
CVP analysis.
Net operating income
is closer to
net cash flow.
Consistent with standard
costs and flexible budgeting.
Advantages
Easier to estimate profitability
of products and segments.
Impact of fixed
costs on profits
emphasized.
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Profit is not affected by
changes in inventories.
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Impact of JIT Inventory Methods
In a JIT inventory system . . .
Production
tends to equal
sales . . .
So, the difference between variable and
absorption income tends to disappear.
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