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Contribution Margin

General

Contribution Margin

The amount left from each sale after subtracting variable costs, which goes toward covering fixed costs and, beyond that, profit.

Definition

Contribution margin is what's left from a sale after subtracting only the variable costs tied to producing it, before fixed costs are considered at all. It's the amount each unit sold "contributes" toward covering the business's fixed costs, and once those are covered, straight to profit.

This is distinct from gross margin, which subtracts total cost of goods sold, sometimes including fixed manufacturing overhead. Contribution margin isolates just the variable piece, making it the key number for break-even analysis and per-unit pricing decisions.

Formula

Contribution Margin per Unit = Selling Price − Variable Cost per Unit

Contribution Margin Ratio = Contribution Margin per Unit / Selling Price × 100

Worked Example

A product sells for $60, with variable costs of $22 per unit.

  • Contribution margin per unit: $60 − $22 = $38
  • Contribution margin ratio: $38 / $60 × 100 ≈ 63%

If fixed costs are $76,000 for the period, break-even volume is $76,000 / $38 ≈ 2,000 units, below that, the business is running at a loss.

Key Things to Know

  • A higher contribution margin lowers your break-even point. More margin per unit means fewer units needed to cover the same fixed cost base.
  • It's the right number for product-mix decisions. When comparing which products to push, contribution margin (not revenue or gross margin) shows which actually helps the bottom line most per unit sold.
  • A negative contribution margin is a red flag, not a fixable overhead problem. If variable costs exceed price, no amount of volume fixes it, the pricing or production cost itself needs to change.
  • Contribution margin ratio is useful for comparing products with different price points. A $5 product and a $500 product can be compared fairly on their margin ratio even though their dollar contribution margins look very different.
  • Discounting erodes contribution margin faster than it seems. A 10% price cut can eat a much larger share of contribution margin than of revenue, since variable costs stay the same regardless of the discount.

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Related Terms

Variable CostsVariable CostsFixed CostsFixed Costs

Frequently Asked Questions

How is contribution margin different from gross margin?
Contribution margin subtracts only variable costs from revenue, while [gross margin](/glossary/gross-margin/) subtracts the full cost of goods sold, which can include some fixed manufacturing overhead. They're related but not calculated from the same cost base.
What does a contribution margin ratio actually tell you?
It shows what percentage of each sales dollar is available to cover fixed costs and contribute to profit. A 40% contribution margin ratio means 40 cents of every revenue dollar goes toward fixed costs and profit, the rest covers variable costs.
Can contribution margin be negative?
Yes, if variable costs exceed the selling price, meaning you lose money on every unit sold before fixed costs even enter the picture. That's a pricing or cost structure problem that needs fixing immediately, not something fixed costs can offset.
Why do businesses look at contribution margin per product line?
It helps identify which products are actually profitable contributors versus which ones barely cover their variable costs, informing decisions about where to focus sales effort or cut a underperforming line.
How does contribution margin relate to break-even analysis?
Break-even volume is fixed costs divided by contribution margin per unit, so a higher contribution margin means you need to sell fewer units to cover your fixed costs and start turning a profit.