There's a number every online seller can recite: their platform's "fee percentage". Etsy is 6.5%. Amazon is 15%. eBay is 13.25%. Mercari is 10%. Easy to remember, easy to plug into a spreadsheet.
These numbers are also wrong. They are the largest single fee, but they are not the total fee. A seller who treats them as the total is consistently surprised when payouts hit their bank.
The fees most calculators don't mention
Pull up a typical "Etsy fee calculator" article ranking on Google. It will compute the 6.5% transaction fee. It will sometimes compute the 3% + $0.25 payment processing fee. That's usually it.
In reality, an Etsy seller in the US pays at least four lines on every order:
- $0.20 listing fee — small but recurring every 4 months or after sale
- 6.5% transaction fee on item + shipping
- 3% + $0.25 payment processing (varies by country: 4% + £0.20 in the UK)
- 12–15% offsite ads attribution if the sale was ad-driven (mandatory at 15% above $10k/year sales, with a $100 cap per order)
The Amazon hidden fee almost nobody talks about
Amazon refunds the referral fee on returns — except they keep 20% as a "refund administration fee" (capped at $5 per return). Most calculators don't model this at all.
Worked example: a $50 item on Amazon at the standard 15% referral. Sale fee = $7.50. If the customer returns it, Amazon refunds $6 of the referral and keeps $1.50. On a 15% return rate, that adds up to $0.225 of margin loss per gross order — small per item, real over a year of inventory.
The 20% non-refunded referral on returns is the single most-overlooked Amazon fee. It scales linearly with return rate and is invisible until you reconcile.
eBay's fees stack into 25%+ on competitive categories
eBay's "final value fee" is 13.25% on most categories. Add the $0.30 per-order fee. Add 10% for promoted listings (which most sellers in competitive categories run because organic ranking has effectively been replaced by paid placement). Add the international surcharge for cross-border sales.
The result on a $50 item: 13.25% FVF + 10% promoted + payment fees + per-order fee = roughly 25% of gross revenue. The 13.25% number that everyone quotes is barely half the actual cost of selling on eBay.
Mercari's fixed fee is brutal at low prices
Mercari's 10% selling fee + 2.9% + $0.50 payment processing looks reasonable on a $30 item: roughly $4.40 of fees, ~15% effective rate.
On a $5 item the same fee structure costs $1.15, or 23% of revenue. Mercari is extremely punitive on low-priced goods, which is why successful Mercari sellers cluster around $15+ price points.
What to do about it
Three habits that prevent fee surprises:
- Compute the all-in fee rate, not the headline rate. For Etsy this is closer to 12–14% effective; for Amazon 18–20%; for eBay 14–25% depending on promotion.
- Run cross-platform comparisons before listing. Same item, $50 + $5 shipping, you might net $40 on Mercari, $39 on Etsy, $35 on Amazon, $32 on eBay with promoted listings.
- Re-run the calculation when fees change. Etsy raised the offsite ads rate in 2022. Mercari brought back its 10% selling fee in 2024 after experimenting with zero-fee. Numbers in old blog posts are usually stale.
Our marketplace fee calculator models all of these — including the Amazon 20% non-refunded referral, Etsy's country-specific payment processing, and eBay's tiered FVF. It also runs a side-by-side comparison so you can see where the same item nets the most.