Contribution Margin
Contribution margin is the revenue left from a sale after subtracting the variable costs of delivering it, the money each sale contributes toward covering fixed costs and, beyond that, profit.
What it means
Take the price of a product, subtract everything that scales with each unit sold, cost of goods, shipping, payment fees, variable labor, and what remains is the contribution margin. It answers a question a company-wide P&L can't: does this specific product, channel, or customer actually make money?
It's usually expressed per unit or as a percentage of revenue. A 40% contribution margin means 40 cents of every revenue dollar is available to cover rent, salaries, and the rest of your fixed costs before anything becomes profit.
Contribution margin by SKU and by channel is one of the most revealing views in a business, and one most owners never see, because standard bookkeeping reports the company as a single blended number.
Why it matters for owner-operated businesses
Without contribution margin by segment, you can be scaling the products and channels that quietly lose money while starving the ones that fund everything. It's the number that tells growth from bleeding.
It's the foundation under pricing, channel strategy, and whether your customer acquisition actually pencils out.