How we calculate

Fee figures

Every default fee comes from the platform's own official fee or pricing page, read on 2026-10-22. Each fee field links its source in its help text and in the Sources section of the page. We use standard US rates for the most common case. Category-specific rates, seller tiers, promotions and other countries can differ, so every fee is editable. Fees we couldn't confirm are marked UNVERIFIED and listed on the Sources page.

Fee bases

Platforms charge fees on different amounts: some on the item price only, some on price plus shipping, some also on sales tax. Each calculator's formula section shows exactly which amount each fee uses, following the platform's fee page.

Using your own numbers

Every platform calculator has a "Use my own numbers" section. Each fee field shows a Default badge linking the official source and the date we checked it. Once you change it, it shows a Your number badge with a button to reset that field, and the result says which of your own numbers it used. Percentages must be between 0 and 100, and amounts can't be negative; anything invalid falls back to the nearest allowed value or the default, and the field tells you.

Sales tax

You can enter a sales tax rate. Tax base: item price + shipping charged to the buyer (sales tax = rate × (item price + shipping charged)). We use it only because some fees are charged on the tax. Tax is never counted as your profit. Who collects and remits sales tax depends on the platform and where you and your buyer are; the field says what's typical, but this is not tax advice.

Profit

Profit = what the buyer pays you (item price plus any shipping you charge) − platform fees − your shipping label − what you paid for the item − other costs. Margin is profit divided by the item price. Income tax, returns, refunds and chargebacks aren't included.

Example figures

Your own numbers (price, item cost, label cost) start with simple example figures so the calculator shows a result. They're marked as examples; replace them with yours.

Privacy

Everything runs in your browser. Numbers you change are saved in your browser's local storage on this device only and never sent anywhere. See Privacy.

All results are rough estimates, not a guarantee, not financial advice. Check your platform's fee page and your actual order statement.

Last updated October 22, 2026.