How the numbers are checked
What every figure on this site rests on, and the two checks a build has to pass before a page is published.
The source is the platform's own fee page
Every rate, threshold and fixed fee is copied from the page where the platform publishes it, and each is stored with that page's address and the date it was read. Rates were last verified on 2026-09-13. No rate is taken from another calculator.
First check: the arithmetic reproduces the platform's examples
eBay prints two worked examples on its fee page: a $424.00 sale that costs $58.06, and a $10,070.00 trading card sale that costs $1,054.55. The calculator must produce both, to the cent, or the site is not built. The second one also settles how eBay rounds: $1,054.545 becomes $1,054.55, which is rounding half up. The eBay page is checked against 13 worked sales in all, including a sneaker sale on both sides of the $150 threshold and a watch that crosses two rate bands.
The other platforms publish no worked examples, so their checks are sales worked by hand from the published rates. Where a platform states how it rounds, as Cash App's terms do with banker's rounding, that rule is used and a sale that lands on a half cent is checked against it. Where a platform does not say, the page states that the rounding is an assumption.
Where a platform publishes only a range, or its own pages disagree, the page shows the range and names both sources, rather than a number chosen from inside it.
Second check: the rates are still on the page
A calculator can reproduce last year's examples with last year's rates. So before publishing, the exact wording of each rate is fetched again from the platform's page. If eBay's page no longer says "13.6% on total amount of the sale up to $7,500", the build stops until the rate is read again.
The calculator that runs in your browser and the one those checks run are two implementations of the same schedule, and they are compared on every worked sale. If they disagree by a cent, nothing is published.
What these pages do not claim
A result here is what a platform's published schedule gives for the numbers you enter. It is not what a platform will charge your account, which can differ with promotions, negotiated rates, credits and refunds that only the platform can see.
Not affiliated with eBay, PayPal, Stripe, Cash App, Depop, Mercari, Reverb, Venmo or Whatnot, and not endorsed by any of them.