How we calculate profit after costs

Margin Keep estimates contribution margin for a cart or simulation. That means profit after product cost and the everyday selling costs you set in Get started — not full accounting profit.

The simple math

1. Start from selling price after discounts.
2. Subtract product cost (known from Shopify or your spreadsheet, estimated from your default cost %, or missing).
3. Subtract card fees, packaging, and shipping help from Get started.

What is left is contribution margin. It does not include ads, rent, salaries, taxes, or returns.

Cost confidence

• High — real unit costs for the items in play
• Estimated — using your default product cost %
• Missing or low — not enough to block checkout; Margin Keep only warns or logs

Estimated margin protected

On Overview, estimated margin protected is the profit we think you kept (or would have kept) when a rule would have blocked or did block a cart that fell below your floors. Treat it as a guide — it gets more trustworthy as cost coverage improves.