Every SellerCounter calculator uses fees from the platform’s own help pages, checked at least every 30 days. This page explains where the numbers come from, how the math works and what the calculators leave out.
Where our fee data comes from
| Calculator | Official fee source | Fees last checked |
|---|---|---|
| Amazon | Amazon: Selling on Amazon pricing and Amazon’s 2026 FBA rate card | 25 October 2026 |
| Depop | Depop Help Centre: Seller fees and charges | 21 October 2026 |
| eBay | eBay Help: Selling fees and Store selling fees | 22 October 2026 |
| Etsy | Etsy Fees & Payments Policy and payment processing fees | 25 October 2026 |
| Grailed | Grailed Help Center: What are the fees? and payment processing fees | 10 November 2026 |
| Mercari | Mercari Help Center: Fees on Mercari | 22 October 2026 |
| PayPal | PayPal: US business fees and consumer fees | 1 November 2026 |
| Poshmark | Poshmark Support Center: What are the fees for selling on Poshmark? | 22 October 2026 |
| TikTok Shop | TikTok Shop Seller University: referral fees by category | 25 October 2026 |
| Venmo | Venmo: About Venmo fees | 1 November 2026 |
| Vinted | Vinted: Price List and Vinted fee | 10 November 2026 |
| Whatnot | Whatnot Help Center: Whatnot seller fees | 22 October 2026 |
When a platform’s help pages don’t cover something, such as the date a change took effect, we use the platform’s own announcements, then reputable news coverage, and link the source.
How often we check
We check every platform’s fees at least every 30 days, and straight away when a platform announces a change. Each calculator shows the date of its last check under its fee table.
Each fee is stored in one place. When it changes, every calculator and page that uses it updates at once, and the change is added to our public fee changelog. The latest changes:
| Date | Platform | What changed | Before | After | Details |
|---|---|---|---|---|---|
| Poshmark | Overweight parcels shipped without an upgrade (US) | Covered by Poshmark | Taken from your earnings | The upgrade price is deducted instead: $5 or $10, or $15 for 15–25 lb on one label. Source | |
| Etsy | Share & Save refund (holiday offer) | 4% | 6.5% | Covers the whole transaction fee on eligible orders until 4 January 2027, then returns to 4%. Source | |
| Amazon | FBA holiday peak fulfillment fees | Standard rate card | About $0.32 a unit more on average | Until 14 January 2027. Storage rises to $2.40 per cubic foot for standard-size items from October to December. Source | |
| Vinted | Buyer fee renamed | Buyer Protection fee | Vinted fee | Same calculation, usually 5% + $0.70, paid by the buyer. Refunds moved to a separate refund policy. Still no selling fee. Source | |
| Whatnot | Commission for higher-volume sellers | Flat 8% | 8% down to 6.5% or lower | Rates now step down with sales over each 4-week period. Sellers under $15,000 still pay 8% in most US categories. Source | |
| Etsy | Regulatory operating fee, France, Italy and Spain | 0.47%, 0.32% and 0.72% | 1.14%, 0.80% and 0.88% | Hungary got a new 1.97% fee on the same date. Source | |
| Etsy | Regulatory operating fee, United Kingdom | 0.32% | 0.48% | On the item price and shipping. Source | |
| Grailed | Seller commission | 9% on every sale | 6% under $120 (at least $1.99), 9% from $120 | Grailed added a reduced rate for sales under $120. Payment processing is charged separately. Source | |
| Amazon | Fuel and logistics surcharge on FBA fees | None | 3.5% | On FBA fulfillment fees in the US and Canada. Amazon calls it temporary, with no end date. Source | |
| Depop | US and UK: Boosting fee | 8% | 12% | For boosts made from this date. Earlier boosts keep 8%. Source |
How the calculations work
- Fees follow each platform’s own rules. Each fee is charged on the amounts the platform names: for example, Whatnot’s commission on the item price only, and Mercari’s selling fee on the item price plus shipping the buyer pays.
- Each fee is rounded to the nearest cent, as platforms do on their statements. A result can occasionally differ from a statement by a cent. For a whole Whatnot show it can differ by a few cents, because Whatnot rounds each order separately.
- Profit = what’s left after the platform’s fees − your shipping cost − what you paid for the item, minus any other costs you enter.
- “What price do I need?” uses the same math to find the lowest price, to the cent, that reaches the profit you enter.
What the calculators don’t include
- Income tax or self-employment tax on your profit.
- Discounts, offers and promotions you run, unless the calculator asks about them.
- Returns, refunds and chargebacks.
- Currency conversion when you sell to buyers abroad.
- Optional programs a calculator doesn’t list.
For your exact fees, your platform’s sale receipt or statement is always the final word.
How we test the calculators
Before a calculator goes live, we check it against worked examples calculated by hand from the platform’s fee rules, and against hundreds of automated checks across the site. We run those checks again after every change.
Corrections
If you think a fee or result is wrong, email info@sellercounter.com with the calculator and the numbers you used, or a screenshot of your sale receipt. We check it against the platform’s fee page, fix the calculator if needed and record the correction in the fee changelog.
Independence
SellerCounter isn’t affiliated with any marketplace. No platform pays us or reviews our numbers.