How we calculate marketplace fees

Our basic rule

We separate buyer checkout, seller revenue, marketplace fees, and business costs. They are not the same number. Sales tax can be part of a platform’s fee base even though that tax is never seller revenue. Shipping charged to a buyer is revenue, while the shipping label is a cost.

Where the rates come from

We use current public marketplace policies and seller announcements wherever possible. Every calculator links to its main official sources and displays a last-checked date. If a platform changes a rate after that date, treat the result as a scenario—not a payout quote.

How each tool rounds

Each visible fee line is rounded to the nearest cent before the lines are totaled. That matches how most sellers audit a transaction, but a marketplace may round internal calculations in a different order. A one-cent difference can therefore be normal.

Scope and freshness safeguards — 17 October 2026

Amazon selects the non-peak or holiday table by date. Automatic estimates stop after January 14, 2027 until the next schedule is verified; explicitly selected historical scenarios remain available. Apparel and dangerous goods are unsupported. Add selling-plan charges as costs. Grocery has no minimum referral fee. Official Amazon seasonal tables and referral fees are the rate references.

Etsy assumes one US listing and USD settlement. Conversion, instant-transfer charges and tax on seller fees are excluded. Offsite Ads are capped at $100 per order; the qualified 12% rate applies for the shop’s lifetime under Etsy’s policy. eBay assumes one item per order and selected no-Store categories. Guitar and bass insertion fees are zero; international charges and account surcharges are excluded.

Facebook Marketplace

Local pickup includes entered packaging and other costs, with no platform checkout fee. Shipped checkout is an editable scenario, not a verified current Meta tariff. Confirm availability, rate, minimum and fee base in your seller account. The 10%/$0.80 example is not an official current quote.

Target-price outputs are estimates within a $1,000,000 search limit, not a guarantee of the globally lowest cent. Sales tax is held constant. Platform rounding and account adjustments can differ. A warning appears on calculator results when the recorded review is more than 30 days old; review dates are not automatically refreshed.

Amazon FBA

The Amazon tool combines a category referral rule with a simplified 2026 non-apparel fulfillment schedule. Fulfillment depends on price band, packaged size tier, and shipping weight. The current temporary fuel and logistics surcharge is calculated as a percentage of the fulfillment fee. The tool intentionally does not guess storage, inventory placement, returns, or aged-inventory charges.

Etsy

The Etsy tool models one US listing or renewal, the transaction fee, US Etsy Payments processing, and an optional Offsite Ads rate. The transaction fee and Offsite Ads use the item plus shipping charged for a US seller; payment processing also includes applicable buyer sales tax. Your own postage is kept separate.

eBay

The eBay tool models common categories for a US seller without a Store. The final value fee and promoted rate use the total checkout base, including buyer sales tax. Tax is removed again before profit because it is not seller revenue. The per-order fee depends on whether the total is at or below $10.

How to verify a result

1. Use the packaged dimensions and shipping weight—not just the product itself.
2. Match the exact marketplace category and seller plan.
3. Compare the fee base: item only, item plus shipping, or full checkout including tax.
4. Add variable costs the calculator cannot know, such as returns, storage, packaging, labor, and overhead.
5. Confirm important decisions with the platform’s official calculator or a recent payout statement.

Found a rate that changed? Please send the official source and the date you saw it. We prefer a corrected table over a confident stale answer.