Ecommerce Profitability

How to Calculate Ecommerce Profit

Real ecommerce profit is the order value minus the full variable cost stack — not revenue minus COGS. This guide shows the order of subtraction and the numbers worth keeping separate.

Last reviewed Calculation methodology

The ecommerce profit formula

Order revenue = Selling price + Shipping charged Non-ad costs = COGS + Shipping + Fees + Return loss + Other variable costs Net profit = Order revenue − Non-ad costs − Advertising cost

The important part is not the arithmetic; it is keeping the cost layers separate. COGS tells you product economics, contribution before ads sets your acquisition ceiling, and net profit tells you what is left after the CPA you actually paid.

Worked example

On an $80.00 order, the example spends $40.70 before advertising and $20.00 on acquisition. Contribution before ads is $39.30, so maximum break-even CPA is $39.30. The order ultimately keeps $19.30, a 24.1% net margin.

Its actual ROAS at that CPA is 4.00x, while break-even ROAS is only 2.04x. That gap is the room available for profit.

Costs ecommerce sellers commonly miss

  • Seller-paid fulfilment. Free shipping still has a real cost.
  • Percentage and fixed payment fees. Small numbers matter because they come out of contribution, not gross revenue.
  • Return/refund economics. Refunds can keep ad cost, handling and two-way shipping even when revenue disappears.
  • Packaging and pick-and-pack. They scale with order volume and belong in unit economics.
  • Advertising / CPA. Revenue can rise while order profit falls if acquisition gets more expensive.

Why contribution before ads matters

Contribution before ads is revenue minus every variable cost except acquisition. It is the maximum amount an order can spend on paid acquisition before profit reaches zero. In other words, it is your maximum break-even CPA.

Divide order revenue by that ceiling and you get break-even ROAS. See the break-even ROAS guide for the ratio view.

Where fixed costs belong

Salaries, rent, software and subscriptions do not normally change with one additional order, so they are not included in this order-level calculator. Once you know contribution per order, a store-level break-even calculator can divide monthly fixed cost by contribution to find how many orders the business needs to cover overhead.

Frequently asked questions

Is gross margin the same as ecommerce profit margin?

No. Gross margin usually stops after COGS. Ecommerce net margin after acquisition also accounts for fulfilment, platform/payment fees, advertising and the other variable costs you entered.

Should returns be a percentage or a dollar amount?

A dollar loss per order is often safer for planning because return economics differ by product. Calculate the average economic loss your historical returns create and enter that amount rather than assuming every return loses the full sale value.

Can I use this for organic orders?

Yes. Set ad cost to zero. The result becomes order profit before fixed overhead, and actual ROAS is intentionally left blank because there was no ad spend.

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