Contribution margin subtracts variable costs from sales and shows what an additional sale contributes toward fixed costs and profit; gross margin subtracts cost of goods or services under the business's accounting policy. A $100 sale with $35 of variable cost has a $65 contribution margin, while a $100 sale with $55 of cost of goods has a 45.00% gross margin.
What contribution margin vs gross margin means
Contribution margin is sales revenue minus variable costs, while gross margin is gross profit divided by revenue after cost of goods or services. Contribution margin supports volume, break-even, and incremental-sale decisions; gross margin describes a broader direct-cost relationship for a stated reporting period.
| Selling price | $100 per unit |
|---|---|
| Variable cost | $35 per unit |
| Contribution | $65 per unit |
| Cost of goods | $55 per unit |
| Gross margin | 45.00% |
Contribution margin vs. gross margin: which decision does each support?: worked example
A shop sells one item for $100. The item has $35 of materials, shipping, and transaction costs that rise when one more item is sold, so the contribution from that sale is $65. Its financial statement classifies $55 of inventory cost in cost of goods, leaving $45 gross profit and a 45.00% gross margin. The two measures need not match because they answer different questions and use different cost pools.
How to calculate contribution margin vs gross margin
For a unit decision, contribution per unit = selling price minus variable cost per unit. For a reported gross margin, gross margin = (revenue minus cost of goods or services) divided by revenue. Mark whether each cost changes with one more unit, then retain the accounting classification separately.
Use the relevant inputs with these related Calculatort pages: break-even units · profit-margin calculation · cash-flow guide.
Common mistakes
Do not call every expense variable, put a monthly lease into one unit's variable cost without a stated driver, or compare contribution dollars with a gross-margin percentage as if they used the same denominator.
Where this calculation stops
A cost can change with volume over one range and become fixed over another. Returns, capacity limits, commissions, taxes, and accounting classification can alter the decision; this simplified case is not a financial statement.
Source and verification
The U.S. Small Business Administration defines contribution margin as sale price less variable cost and uses it in its break-even formula. Read the named source. Verify the source date and the controlling statement, agreement, payroll record, or accounting record before relying on the illustrated result.