Contribution Margin Formula

What is Contribution Margin?

The contribution margin formula is used to calculate contribution margin. Contribution margin is the difference between the revenue and the variable costs of a business.

Analysis of Contribution Margin
Variable Costs Contribution Margin


The contribution margin formula is written as:

Contribution Margin (CM) = Revenue from Sales (R) – Variable Costs (VC)

Sales Revenue used in Contribution Margin Formula

In accounting sales revenue refers to the monetary amount from the sale of goods and services in which the business normally trades and which were bought for the purpose of resale. Sales returns and allowances, and sales discounts are deducted to arrive at the sales revenue figure to use in the contribution margin formula calculation.

Variable Costs used in Contribution Margin Formula

Variable costs are those costs which vary in relation to the activities carried out by the business. One example of a variable cost is the cost of goods sold which is the costs associated with producing the goods which have been sold during an accounting period.

Rearranging the Contribution Margin Formula

The contribution margin formula can be rearranged in numerous ways to provide useful information depending on what information is already known.

For example, if you only know the variable costs and the contribution margin percentage, you can calculate the revenue and the contribution margin using the contribution margin formula.

The table below shows a few ways of rearranging the contribution margin formula.

Contribution Margin Formula Uses
Contribution Margin Formula Use Formula
Calculate contribution margin CM = R – VC
Calculate revenue R = VC + CM
Calculate variable costs VC = R – CM
Calculate contribution margin % CM% = CM / R = (R – VC) / R
Calculate revenue R = VC / (1- CM%)

Example of how to use the Contribution Margin Formula

Suppose a business knows that its variable costs are 200,000 and its contribution margin percentage is 40% and wants to find its contribution margin.

The contribution margin formula tells us that Revenue = Variable costs + Contribution margin. So if contribution margin is 40% of revenue, then variable costs must be the remaining 60% of revenue. This is demonstrated in the diagram below.

Contribution Margin Formula as %
Revenue = 100%
Variable Costs = 60% Contribution Margin = 40%

If variable costs are 60% of revenue it follows that:
Variable costs = 60% x Revenue
Revenue = Variable Costs / 60% = 200,000 / 60% = 333,333

Finally using the contribution margin formula again
Contribution Margin = Revenue – Variable Costs
Contribution Margin = 333,333 – 200,000 = 133,333

The check is that Contribution margin % = Contribution Margin / Revenue = 133,333 / 333,333 = 40%

The contribution margin formula is very useful for calculating the contribution margin of a business. The contribution margin (sometimes referred to as the contribution sales ratio) is an important concept as it represents the true income of a business.

Last modified November 6th, 2016 by Michael Brown

About the Author

Chartered accountant Michael Brown is the founder and CEO of Double Entry Bookkeeping. He has worked as an accountant and consultant for more than 25 years in all types of industries. He has been the CFO or controller of both small and medium sized companies and has run small businesses of his own. He has been a manager and an auditor with Deloitte, a big 4 accountancy firm, and holds a BSc from Loughborough University.

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