How these calculators work

Each calculator applies the marketplace's published seller fee schedule: the category percentage, any fixed per-order charge, payment processing, regulatory fees and VAT where the market applies it.

Rates are stored as structured data rather than baked into the page, so when a marketplace changes its schedule the number changes in one place and every calculator that uses it updates.

This is where most manual calculations drift, and it differs by platform. eBay charges its final value fee on the total the buyer pays, including postage. Poshmark charges its commission on the item price only, because it bills shipping separately. Whatnot splits the difference: commission on the item price, processing on the whole order.

Each calculator charges the fee on the correct base for that platform, and the basis is printed next to every fee line so you can check it.

Every fee line prints its own arithmetic — the rate, the amount it was applied to, and any fixed charge. A banded rate shows every band it crossed, not a single blended percentage.

This is deliberate. A number you cannot check is a number you cannot act on, and an unexplained calculator is not much more useful than a guess.

Every page carries the date its rates were last checked against the marketplace's own fee documentation, and links to that documentation.

Marketplace fees change, sometimes quietly. If a page was verified months ago and your payout does not match, trust your payout and check the marketplace's current schedule.

These calculators cover marketplace fees and the cash costs you enter. They do not model returns and refunds, unsold inventory, storage, your own time, currency swings over time, or tax treatment — all of which affect real profit.

They also do not tell you where to sell. Fees decide margin; audience decides whether there is a sale at all, and the second question comes first.