Real margin: what you actually keep from every sale

"I buy it for 8 and sell it for 24, so I make 16." Almost everyone does this math at the start, and it is almost always wrong. Between the selling price and what ends up in your pocket there are costs you only notice when the statements arrive.

What real margin is

Your real margin per sale is what you keep from a single order after subtracting every cost tied to that order. It does not yet include monthly subscriptions and fixed expenses: those come later, when you calculate break-even.

The basic formula is:

real margin = revenue − product cost − shipping − packaging − fees

where revenue is what the customer pays, including shipping if you charge for it.

The costs people forget

The shipping you pay. Even if you charge the customer for shipping, what the carrier actually costs you can differ from what you bill.

Store fees. Marketplaces and platforms usually keep a percentage of each sale, often calculated on shipping too, and sometimes a fixed fee per order or per listing. Every platform has its own rules and updates them, so always check the current rates.

Payment fees. Whoever collects the money for you (the platform or a payment network) typically keeps a percentage plus a small fixed fee per transaction.

VAT on fees. If you sell without an EU VAT number, some platforms charge VAT on their own fees. It is a small amount per order, but across hundreds of sales it adds up.

Packaging and materials. Boxes, mailers, thank-you cards: a few cents each, and they still count.

A complete example

A print-on-demand poster sold on a marketplace:

• price: €24.00 plus €4.50 shipping, so revenue of €28.50;
• printing cost: €8.20;
• shipping paid to the supplier: €4.50;
• store and payment fees, including VAT on fees: €4.23.

Real margin: 28.50 − 8.20 − 4.50 − 4.23 = €11.57, or about 41% of revenue. A long way from the €16 of the back-of-the-envelope math.

From margin to decisions

Once you know your real margin, three questions get easy:

• How many sales do I need to cover fixed costs? Divide your monthly fixed costs by your margin. That is your break-even point.
• How much can I spend on ads? Your cost per sale has to stay below your margin, or every sale loses you money.
• Is my price right? If your margin is below 25-30%, any surprise (a return, a supplier price increase) pushes you into a loss. Consider raising the price or switching suppliers.

Key takeaways

• Real margin is revenue minus every cost of the order.
• Count shipping, store and payment fees, VAT on fees and packaging.
• Use your margin to calculate your break-even point and your maximum ad budget.