Contribution Margin Calculator
Calculate contribution margin per unit and in total, the contribution margin ratio, operating income, break-even sales and operating leverage.
Contribution margin is what is left from sales after the costs that rise and fall with volume, and it is the money available to pay fixed costs and then generate profit. Managers use it to decide which products to push, whether a discount still pays, and how sensitive profit is to a drop in sales. Enter figures per unit or as totals from your income statement.
How to use this tool
- Choose whether you have per-unit figures or totals for a period.
- Enter the price and variable cost per unit with units sold, or total sales and total variable costs.
- Add fixed costs to see operating income, break-even sales and operating leverage.
- Use the contribution margin income statement to check each line.
Formula
Contribution margin = Sales − Variable costs
CM ratio = Contribution margin ÷ Sales × 100
Operating income = Contribution margin − Fixed costs
Degree of operating leverage = Contribution margin ÷ Operating income
Variable costs include materials, direct labour paid per unit, sales commissions, shipping and payment fees. Rent, salaries and depreciation are fixed. Break-even sales equal fixed costs divided by the CM ratio. Cost classification depends on the business and relevant activity range; salaries, rent and depreciation are not universally fixed. Leverage assumes selling price, sales mix, unit variable cost and fixed cost remain unchanged.
Example
A product sells for $50 and costs $30 in variable costs, so each unit contributes $20 and the CM ratio is 40%. Selling 1,000 units gives $20,000 of contribution margin; after $12,000 of fixed costs, operating income is $8,000. Operating leverage is 20,000 ÷ 8,000 = 2.5, so a 10% rise in sales would lift operating income by about 25%.
Frequently asked questions
What is the difference between contribution margin and gross margin?
Gross margin subtracts cost of goods sold, which can include fixed production overhead. Contribution margin subtracts only variable costs, including variable selling costs such as commissions, so it shows how profit responds to volume.
What is a good contribution margin ratio?
The useful ratio depends on fixed costs, volume and capacity. A larger ratio provides more contribution per sales dollar under otherwise unchanged assumptions; this tool does not supply industry benchmarks.
Can contribution margin be negative?
Yes. If modeled variable costs exceed revenue, contribution is negative. The result describes the entered cost structure; repricing, capacity constraints and effects on other products need separate analysis.
Last updated: 2026-10-30