Contribution Margin

Contribution margin answers one question: does one more sale help, once its own direct costs are paid? It is the number behind break-even and behind decisions about which product or channel to push. A sale with a thin margin needs far more volume to matter than one with a healthy margin. Ignore it and a business can chase revenue that barely covers its own delivery.

It differs from gross margin, which is usually reported for the whole business and often counts some fixed production costs. Contribution margin works at the level of a single sale, which makes it better for pricing and mix decisions.

• Subtract only the costs that rise with each extra sale, not general overhead.
• Show it as an amount and as a percentage of the price.
• Compare it across products, channels and customer types instead of relying on one blended average.
• Divide fixed costs by the contribution margin per sale to find how many sales reach break-even.
• Question any channel with a low margin before sending it more volume.

Contribution margin is price minus variable costs, the costs that only exist because a sale happened. For a service these are delivery time, subcontractors, payment fees and sales commission. For a product they include materials, packaging and shipping. Rent, salaries and software subscriptions are fixed costs and stay out.

The result can be shown per sale, in money, or as a percentage of the price. Both views are useful.

• Leaving out the cost of the team's own delivery time.
• Counting fixed costs as variable, which makes every sale look unprofitable.
• Averaging across products and hiding the weak one.