Contribution Margin Calculator — CM Ratio & Break-Even
The contribution margin tells you how much each unit sold contributes toward covering fixed costs — and then to profit. Enter the selling price, variable cost per unit, total fixed costs and sales volume to get the CM per unit, CM ratio, break-even point and operating profit instantly.
Selling price minus variable cost — what each unit contributes to covering fixed costs and profit
- 1
Selling price per unit
50 - 2
Variable cost per unit
20 - 3
Contribution margin per unit
50 − 20 = 30
How does this calculator work?
Contribution margin per unit = Selling price − Variable cost. Divide total fixed costs by CM per unit to find break-even volume. A CM ratio of 60 % means $0.60 of each revenue dollar goes toward fixed costs then profit. Operating profit = (CM × units sold) − fixed costs.
Formula
How this is calculated
Contribution margin (CM) is the amount left from each unit's revenue after subtracting the costs that vary directly with production (materials, direct labour, packaging). Unlike gross profit, it isolates the variable component so you can see how fast you recover fixed overhead. A CM ratio of 60 % means every dollar of revenue contributes 60 cents toward fixed costs and profit.
Break-even analysis divides total fixed costs by the CM per unit: below that volume you make a loss; above it every additional unit generates profit at the CM rate. This makes the break-even point a critical planning figure — it tells you the minimum sales volume needed to stay solvent.
Cost-volume-profit (CVP) analysis extends this: it shows how changes in price, variable costs or volume ripple through to profit. The assumption is that selling price and variable cost per unit are constant (linear model). In reality, bulk discounts, overtime, and volume-driven price changes can make the relationship non-linear — treat the break-even as an approximation and stress-test with different price scenarios.
Frequently asked questions
Gross profit subtracts the full cost of goods sold (which may include some fixed manufacturing overhead) from revenue. Contribution margin subtracts only the variable costs, leaving fixed costs to be covered from the total CM pool. CM is more useful for pricing and break-even decisions; gross profit is the standard reported P&L figure.
Yes — if variable cost per unit exceeds the selling price, the CM is negative and each additional unit sold deepens the loss. No amount of volume can make a product with a negative CM profitable; price must increase or variable costs must fall.
Multiply the CM ratio by any revenue increase. If your CM ratio is 40 % and you grow revenue by $50,000, you add $20,000 to profit (assuming fixed costs don't change). This is the leverage effect of operating structure: higher CM ratios amplify both gains and losses.
TG we-Calculate Editorial Team. (2026). Contribution Margin Calculator — CM Ratio & Break-Even [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/contribution-margin-calculator
TG we-Calculate Editorial Team. "Contribution Margin Calculator — CM Ratio & Break-Even." TG we-Calculate. 2026. https://we-calculate.com/calculator/contribution-margin-calculator.
TG we-Calculate Editorial Team, "Contribution Margin Calculator — CM Ratio & Break-Even," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/contribution-margin-calculator
@misc{wecalculate_contribution_margin_calculator, title = {Contribution Margin Calculator — CM Ratio & Break-Even}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/contribution-margin-calculator}}, year = {2026}, note = {TG we-Calculate} }
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