ADSSystem

Contribution margin calculator

What each unit contributes after variable costs, how many units cover the fixed base, and where profit starts.
In one line

Enter price, variable cost and fixed costs to get contribution per unit, contribution ratio, break-even units and operating profit.

Contribution margin = Price − Variable cost per unit
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$
Goods, shipping, processing, per-unit ad cost.
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Contribution per unit -
Contribution ratio-
Break-even units-
Operating profit-
Contribution margin pays the fixed costs first. Only what survives that is profit.
Where each dollar of revenue goes
What survives the variable costsContribution $33 per unit45%Variable cost$27.0033%Fixed cost share$20.0022%Operating profit$13.00WHERE EVERY DOLLAR OF REVENUE GOES

The formula

Contribution margin = Price − Variable cost per unit

Contribution margin is not gross margin

Gross margin subtracts the cost of goods from the price. Contribution margin subtracts every cost that moves with the unit – goods, but also shipping, payment processing, packaging, returns provision and, if you want the number that matters for growth, the acquisition cost of the order.

  • That distinction decides whether growth helps.
  • A product with a healthy gross margin and a heavy per-order logistics cost can have a contribution margin near zero, which means selling more of it changes nothing except how busy the warehouse is.
  • Contribution margin is the only per-unit number that answers the question “does one more sale make us better off?”

Break-even is a unit count, not a feeling

Contribution per unitUnits to cover $18,000
$101,800
$20900
$33546
$45400
$60300
Fixed costs divided by contribution per unit gives the number of units that pay for the base. Everything after that unit contributes to profit at the full contribution rate, which is why the last quarter of a good year looks disproportionately profitable – the fixed costs were already paid by October.

The lever nobody pulls first

Three ways to move break-even: raise price, cut variable cost, cut fixed cost. Most teams reach for the third, which is slow and painful. The first is usually the strongest and the least attempted.

  • At a $60 price and $27 of variable cost, a five percent price rise adds $3 to contribution – a nine percent improvement – and drops break-even from 546 units to 500.
  • Cutting variable cost by the same $3 does exactly the same thing, but supplier negotiations take months and price changes take an afternoon.
  • The reason people avoid the price lever is volume risk, which is a real concern and also a testable one.

The trap

Allocating fixed costs into the unit and then deciding a product is unprofitable.

Allocating fixed costs into the unit and then deciding a product is unprofitable. Spread $18,000 of overhead across 900 units and each one looks like it carries $20 of burden; a product contributing $15 then appears to lose $5 and gets cut. But the overhead does not leave with it. Drop the product and you have lost $13,500 of contribution and kept every dollar of fixed cost.

Fixed costs are a total to be covered, not a tax per unit. Any product with positive contribution margin is helping, even a small one – the only question is whether the shelf space, attention or inventory it occupies could contribute more if used for something else.

Frequently asked

Subtract variable cost per unit from the price. A $60 product with $27 of variable cost contributes $33 per unit, a contribution ratio of 55 percent.
Gross margin subtracts only the cost of goods. Contribution margin subtracts every cost that varies with the unit, which usually includes shipping, processing and often acquisition cost.
Divide total fixed costs for the period by the contribution margin per unit. Fixed costs of $18,000 against $33 of contribution break even at 546 units.