What is contribution margin?
Contribution Margin · Also called contribution profit, CM, variable margin, contribution margin %
Contribution margin is what is left from your sales after the costs that rise and fall with volume. It is what each sale contributes toward fixed costs and profit.
What it is
Start with gross profit, then take off the variable selling costs: trade spend that moves with volume, broker commission, variable marketing and, for online orders, fulfillment and payment fees. This is the view Vaaha Unit Economics uses.
Not all trade or marketing spend moves with units. A one-time slotting fee or a fixed brand campaign belongs with fixed costs, or in a clearly labeled fully loaded view. If your COGS includes allocated fixed production overhead, move that to fixed costs too.
Accountants often deduct some trade spend from revenue instead, for example $0.30 a unit, giving $2.40 net revenue and a 43.75% gross margin. Contribution comes out the same as long as trade spend is counted once: never subtract it from revenue and again below gross profit.
Why it matters
Gross margin can look fine while contribution is negative. If contribution is negative, selling more at the same economics only makes the loss bigger.
Contribution per unit tells you how much volume you need to cover your fixed costs. Positive contribution helps pay for overhead but does not on its own prove you are profitable or have enough cash.
Formula
Contribution = Gross profit − Variable trade spend − Broker commission − Variable marketing − Fulfillment
Contribution margin % = Contribution ÷ Net revenue. Break-even units = Fixed costs ÷ Contribution per unit, assuming price, mix and unit costs hold steady.
Worked example
Contribution and break-even on 10,000 units
- Assume 10,000 units at $2.70 net revenue: $27,000. COGS is 10,000 × $1.35 = $13,500, all variable. Gross profit = $27,000 − $13,500 = $13,500.
- Assume variable trade spend (scan-backs and free fills) of $0.30 a unit: $3,000. Broker commission of 5% of $27,000: $1,350. Variable marketing: $2,400. These are wholesale sales, so there is no fulfillment cost.
- Variable costs below gross profit = $3,000 + $1,350 + $2,400 = $6,750. Contribution = $13,500 − $6,750 = $6,750, which is $6,750 ÷ $27,000 = 25% of net revenue, or $0.675 per unit.
- If your accountant takes the $3,000 off revenue instead, net revenue is $24,000 and gross profit is $24,000 − $13,500 = $10,500. Contribution = $10,500 − $1,350 − $2,400 = $6,750, the same. Subtracting the $3,000 a second time would wrongly show $3,750.
- If your fixed costs are $13,500, break-even = $13,500 ÷ $0.675 = 20,000 units at these economics.
Common mistakes
- Stopping at gross margin and assuming the business is profitable.
- Counting trade allowances twice, once off revenue and again below gross profit.
- Treating one-time slotting or a fixed campaign as if it varied with every unit, or leaving fixed overhead buried in COGS.
- Changing what you include from month to month, so the trend is not real. Write the definition down and keep it.
Common questions
- What contribution margin should I aim for?
- Set the target from your fixed costs, your sales plan and how much risk you can carry, rather than from a universal percentage. Break-even units tell you whether the volume you need is realistic.