How ListMath calculates

Official sources only

Fees, item policies and payout schedules come only from each marketplace's own published pages: its fee pages, seller help center and policy pages. No third-party guides. A marketplace that doesn't publish its fees isn't included.

When pages disagree, the higher cost wins

Marketplaces sometimes publish conflicting or ambiguous figures. ListMath uses the higher cost, so you're more likely to be pleasantly surprised than short.

Unclear means no

When a marketplace's policy doesn't clearly say whether an item is allowed, ListMath says it's unclear, links the policy, and doesn't recommend that marketplace for the item. A wrong "not allowed" costs you less than a wrong "allowed".

Exact money math

Amounts are calculated in whole cents, and each fee is rounded to the cent the way marketplaces round it, so totals match line by line.

Checked every week

A monitor opens every official page each week and flags any wording change for review. Some marketplaces block automated checks; those pages are re-verified by hand each month. Every reviewed change is published in the change log.

Sources and verification dates

What ListMath doesn't know

It doesn't predict demand or the price buyers will pay, and it can't see your account: new-seller payout holds, approvals you already have, or promotions you're enrolled in. Treat results as planning estimates; the marketplace's own fees and policies always apply.