Contribution margin
Contribution margin is what is left of a sale after the costs that rise with each sale: the product, shipping, payment fees, and returns. That leftover money has to cover advertising and everything else. If you keep 20 cents of every dollar, you need $5 of sales for every $1 of ads just to break even.
Theodor Lindfors, Founding Marketer ·
Formula
Contribution margin = revenue - variable costs
How to calculate contribution margin
Let's take a shoe workshop in Mexico as an example. They make leather shoes and sell them online to Mexico and the United States. A pair sells for $180. That $180 is not profit. Leather, making, boxing, shipping to the United States, the card fee, and the pairs that come back all come out first. Contribution margin is what is left after those variable costs, and it is the pool ads have to swim in.
Start with revenue and subtract every cost that moves with the order: cost of goods, shipping and fulfillment, payment processing, and an allowance for returns. Do not subtract rent, salaries, or software. Those are fixed and belong further down the P&L (profit and loss statement). Let's take a shoe workshop in Mexico as an example. They make leather shoes and sell them online to Mexico and the United States. $180 minus $70 product, $12 shipping, $5 fees, $8 returns = $85. Express it as a percentage of revenue so it is comparable across products and periods. $85 / $180 is about 47%.
Contribution margin and break-even ROAS
Divide one by the margin percentage. A 47% margin needs about a 2.13x ROAS (return on ad spend) to break even. A 25% margin needs 4x. Two teams hitting the same 3x ROAS target can be in completely different financial positions. Let's take a shoe workshop in Mexico as an example. They make leather shoes and sell them online to Mexico and the United States. At 47% the workshop is fine at 3x. A thin-margin reseller at 25% is not.
Contribution margin is also the input that makes POAS (profit on ad spend) work. Without a margin figure, profit-based bidding is just ROAS (return on ad spend) with extra steps. Let's take a software company as an example. They sell a subscription tool to plumbing companies. High software margin has a much lower break-even ROAS. Do not copy a software target onto shoes.
What counts as a variable cost
Anything that would not exist if the order did not happen. Product cost, pick and pack, shipping, transaction fees, and the cost of processing returns. Discounts belong here too, since a promotion reduces the contribution of every order it touches. Let's take a shoe workshop in Mexico as an example. They make leather shoes and sell them online to Mexico and the United States. A 20% off sale drops the $180 pair to $144 and the $85 contribution with it.
Returns are the line most teams skip. In shoes the return rate is high enough to reorder which campaigns are actually profitable. A Meta ad that sells the wrong size guide can look efficient on ROAS (return on ad spend) and expensive after send-backs. See payback period for the cash side of the same question, especially if you are comparing a shoe workshop's first pair to a software company's monthly invoice.
Common contribution margin mistakes
- Using gross margin from the annual report instead of order-level variable costs on each shoe-workshop style.
- Applying one blended margin across a catalog where a sandal and a lined boot do not share a cost structure.
- Setting a single ROAS (return on ad spend) target for every campaign regardless of what it sells.
Lemonado
How Lemonado helps with contribution margin
Margin data lives in commerce and finance systems while spend lives in the ad platforms. A shoe workshop's leather cost is not in Meta. Lemonado connects both, so break-even ROAS (return on ad spend) is a number your team can check rather than one someone remembers from last quarter.