how to find marginal cost

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Viberg boot factory, Victoria BC. Marginal costing can help decide what to manufacture, where to manufacture it, and which customers to target: especially when making short-term decisions.

Hugo Chisholm via Flickr (CC BY-SA 2.0)

What Is Marginal Costing?

Marginal costing is a method of cost accounting and decision-making used for internal reporting in which only marginal costs are charged to cost units and fixed costs are treated as a lump sum. It is also known as direct, variable, and contribution costing.

In marginal costing, only variable costs are used to make decisions. It does not consider fixed costs, which are assumed to be associated with the time periods in which they were incurred.

Marginal costs include:

The costs actually incurred when you manufacture a product
The incremental increase in costs when you ramp up production
The costs that disappear when you shut down a production line
The costs that disappear when you shut down an entire subsidiary

In this technique, cost data is presented with variable costs and fixed costs shown separately for the purpose of managerial decision-making.

Marginal costing is not a method of costing like process costing or job costing. Rather, it is simply a way to analyze cost data for the guidance of management, usually for the purpose of understanding the effect of profit changes due to the volume of output.

The direct costing concept is extremely useful for short-term decisions, but can lead to harmful results if used for long-term decision-making, since it does not include all costs that may apply to a longer-term decision. Furthermore, marginal costing does not comply with external reporting standards.

Video: Variable (Marginal) vs. Absorption Costing Part One

Common Use Cases for Marginal Costing

Marginal costing can be a useful tool for evaluating some types of decisions. Here are some of the most common scenarios where marginal costing can provide the most benefit:

Automation investments: Marginal costing is useful to determine how much a firm stands to gain or lose by automating some function. The key costs to take into consideration are the incremental labor cost of any employees who will be terminated versus the new costs incurred from equipment purchase and subsequent maintenance.
Cost reporting: Marginal costing is very useful for controlling variable costs, because you can create a variance analysis report that compares the actual variable cost to what the variable cost per unit should have been.
Customer profitability: Marginal costing can help determine which customers are worth keeping and which are worth eliminating.
Internal inventory reporting: Since a firm must include indirect costs in its inventory in external reports, and these can take a long time to complete, marginal costing is useful for internal inventory reporting.
Profit-volume relationship: Marginal costing is useful for plotting changes in profit levels as sales volumes change. It is relatively simple to create a marginal costing table that points out the volume levels at which additional marginal costs will be incurred, so that management can estimate the amount of profit at different levels of corporate activity.
Outsourcing: Marginal costing is useful for deciding whether to manufacture an item in-house or maintain a capability in-house, or whether to outsource it.

Video: Variable (Marginal) Costing vs. Absorption Costing Part Two

Advantages and Benefits of Marginal Costing

Cost control: Marginal costing makes it easier to determine and control costs of production. By avoiding the arbitrary allocation of fixed overhead costs, management can concentrate on achieving and maintaining a uniform and consistent marginal cost.
Simplicity: Marginal costing is simple to understand and operate and it can be combined with other forms of costing (e.g. budgetary costing and standard costing) without much difficulty.
Elimination of cost variance per unit: Since fixed overheads are not charged to the cost of production in marginal costing, units have a standard cost.
Short-term profit planning: Marginal costing can help in short-term profit planning and is easily demonstrated with break-even charts and profit graphs. Comparative profitability can be easily assessed and brought to the notice of the management for decision-making.
Accurate overhead recovery rate: This method of costing eliminates large balances left in overhead control accounts, which makes it easier to ascertain an accurate overhead recovery rate.
Maximum return to the business: With marginal costing, the effects of alternative sales or production policies are more readily appreciated and assessed, ensuring that the decisions taken will yield the maximum return to the business.

Disadvantages and Limitations of Marginal Costing

Classifying costs: It is very difficult to separate all costs into fixed and variable costs clearly, since all costs are variable in the long run. Hence such classification sometimes may give misleading results. Furthermore, in a firm with many different kinds of products, marginal costing can prove less useful.
Accurately representing profits: Since the closing stock consists only of variable costs and ignores fixed costs (which could be considerable), this gives a distorted picture of profits to shareholders.
Semi-variable costs: Semi-variable costs are either excluded or incorrectly analyzed, leading to distortions.
Recovery of overheads: With marginal costing, there is often the problem of under or over-recovery of overheads, since variable costs are apportioned on an estimated basis and not on actual value.
External reporting: Marginal costing cannot be used in external reports, which must have a complete view of all indirect and overhead costs.
Increasing costs: Since it is based on historical data, marginal costing can give an inaccurate picture in the presence of increasing costs or increasing production.

Conclusion: Marginal Costing Can Be Helpful for Short-Term Decision Making

Marginal costing is a useful analysis tool which usually helps management make decisions and understand the answer to specific questions about revenue.

That said, it is not a costing methodology for creating financial statements. In fact, accounting standards explicitly exclude marginal costing from financial statement reporting. Therefore, it does not fill the role of a standard costing, job costing, or process costing system, all of which contribute actual changes in the accounting records.

Still, it can be used to discover relevant information from a variety of sources and aggregate it to help management with a number of tactical decisions. It is most useful in the short term, and least useful in the long term, especially where a firm needs to generate sufficient profit to pay for a large amount of overhead.

Furthermore, direct costing can also cause problems in situations where incremental costs may change significantly, or where indirect costs have a bearing on the decision.

This article is accurate and true to the best of the author's knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.

P.S.Love on October 01, 2019:

Its Wonderful Quality Content

yashkaran on September 22, 2019:

its good

Saniya khanum on September 02, 2019:

Thank you very much.....the quality of content provided here is very good..

Rafia on April 25, 2019:

this article helps me a lot to enhance my understanding about costing system.yup its helpful

Alisha on April 09, 2019:

Understanding me

Hari krushna on October 03, 2018:

It is simple to understand . It should be very clear

lilsisa on August 06, 2018:

This information is helpful for me

because as a ABM student we tackle this kind of situation

and now I have an idea about different pricing strategies

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Josphat Rwadzisai on April 13, 2018:

its very nice.Thanks

cathrine chitambo on January 29, 2018:

The description is good

question????? on March 14, 2017:

what about contribution costs?

bernie lerry on March 30, 2016:

shallow

mandux on October 30, 2015:

it very nce

ayoub renatus on June 29, 2015:

It good thanks

jk on August 04, 2014:

Clear understood.... good, more practical example next tyme.

PRINCE ERIC AMASU on May 10, 2014:

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Kunal on April 14, 2014:

needs more points of difference and more elaboration

Fernal on May 29, 2013:

Need more disavantages

Alphabet on May 29, 2013:

perfect explanation

Vivek on February 10, 2013:

it is very good for studies............

maulid on November 20, 2012:

is good

Paddington S Kuimba on May 03, 2012:

Pretty fine ,but, a little elaboration would be essential to those who lack an accounting depth....

Divya choubey on January 13, 2012:

Need to explain it with some examples.

Godbless makundi on January 05, 2012:

it is good

Collins Indeje on December 04, 2011:

Quite satisfactory.My question was solved.

Shanu on November 04, 2011:

Need more current statements

$0.06 on February 07, 2011:

fairly good bu more explanation could do the trick

Samir Kumar on March 17, 2010:

It is good but it will be best if you explain with a simple example.It will beneficiary for those students also who is not a commerce background.