Contribution Margin Calculator
Contribution Margin Calculator
What each sale contributes towards fixed costs and profit — per unit, as a share of the price and in total — with operating profit, the break-even volume and how exposed profit is to a fall in sales.
Contribution margin
A price of $450, variable cost $279 a unit, 2,400 units a month and fixed costs of $3,20,000 a month
Contribution margin, profit and break-even
- P
- selling price per unit, net of tax
- V
- variable cost per unit
- Q
- units sold in the period
- F
- fixed costs for the same period
Worked example
A price of $450, variable cost $279 a unit, 2,400 units a month and fixed costs of $3,20,000 a month
Contribution per unit = 450 − 279 = $171
Ratio = 171 ÷ 450 = 38.00%
Total contribution = 171 × 2,400 = $4,10,400
Operating profit = 4,10,400 − 3,20,000 = $90,400
Break-even = 3,20,000 ÷ 171 = 1,871.35, so 1,872 units; margin of safety 22.0%, operating leverage 4.54
The same business at three prices (variable cost 279, 2,400 units, fixed costs 3,20,000)
| Price | Contribution ratio | Operating profit | Break-even units |
|---|---|---|---|
| $400 | 30.25% | $-29,600 | 2,645 |
| $450 | 38.00% | $90,400 | 1,872 |
| $500 | 44.20% | $2,10,400 | 1,448 |
What contribution margin tells you that gross margin does not
Contribution margin splits costs by how they behave, not by where they sit in the accounts. Variable costs rise with each unit sold; fixed costs do not. What each sale leaves after its own variable cost is its contribution — first towards the fixed costs, and once those are covered, into profit. Cost-accounting texts such as Horngren’s use it for cost–volume–profit analysis because it answers the questions a business actually asks: how much does one more sale add? In the example each sale adds $171, or 38% of every sale.
Three figures follow from it. The break-even volume is fixed costs divided by the contribution per unit; here 1,872 units, worked out in more detail by the break-even calculator. The margin of safety is how far sales could fall before the business makes a loss: 22.0% in the example. Operating leverage is total contribution divided by operating profit, and it says how sharply profit moves with sales: at 4.54, a 10% fall in units cuts profit by about 45%. The nearer a business is to break-even, the higher this multiple and the riskier a bad month.
Gross margin, which the profit margin calculator works out, is different: it takes off the cost of goods sold, which can include fixed production overheads, and ignores variable selling costs such as commission or delivery. Contribution margin keeps every cost that moves with volume and nothing that does not. Getting the split right is the whole job, and many costs are mixed — a phone bill with a fixed rental and a usage charge, for instance — so allocate them honestly.
The model assumes one product (or a steady mix), one price and a variable cost that does not change with volume. Keep the period consistent: a month’s fixed costs against a month’s sales. Operating profit here is before interest and income tax. This is arithmetic on the figures you enter, not financial advice.
Frequently asked questions
How do you calculate contribution margin?
Selling price minus variable cost per unit. At a $450 price and $279 variable cost it is $171 a unit, or 38% of the price.
What is a good contribution margin ratio?
There is no single benchmark: it depends on the industry and on how high fixed costs are. What matters is that total contribution comfortably exceeds fixed costs.
What is the difference between contribution margin and gross margin?
Gross margin deducts the cost of goods sold, which can include fixed overheads and leaves out variable selling costs. Contribution margin deducts every variable cost and no fixed cost.
How is contribution margin used for break-even?
Break-even units = fixed costs ÷ contribution per unit. 3,20,000 ÷ 171 = 1,871.35, so 1,872 whole units.
Related calculators
References
- Horngren CT, Datar SM, Rajan MV. Cost Accounting: A Managerial Emphasis. Pearson. Chapter on cost–volume–profit analysis: contribution margin per unit and ratio, break-even point, margin of safety and degree of operating leverage (contribution margin ÷ operating income).
- Garrison RH, Noreen EW, Brewer PC. Managerial Accounting. McGraw-Hill. The contribution format income statement, contribution margin ratio and operating leverage.