The 8% is not what they take. The checkout total is.
Commission is on the hammer. Processing is 2.9% + $0.30 of what the buyer actually paid — item, shipping, and tax. A $20 card with $5 postage is not an $1.60 fee. Then see leftover after the label and what the lot cost you, and the hammer that hits a leftover target.
Worked example, not your lot yet — Whatnot’s published $50 US default, with a $22 cost so leftover is a real number.
Whatnot’s cut
Commission
Processing
Total fees
Effective take on the hammer
Whatnot payout (their “net earnings”)
After your costs
Label + lot + other
Leftover this lot
Show leftover (× lots)
Hammer that hits the leftover target
Free-shipping leftover vs charging
Common questions
How much does Whatnot take per sale?
On a typical US lot Whatnot takes a commission on the item's final sale price (often 8%) plus payment processing of 2.9% + $0.30 on the checkout total — the hammer plus buyer-paid shipping and tax. Whatnot's own $50 example is $4.00 commission + $1.75 processing = $5.75, leaving $44.25. This page does the arithmetic from the rates you type; it is not Whatnot's live schedule.
Is processing charged on shipping?
Yes. Processing is a percentage of what the buyer paid at checkout, not just the hammer. Buyer-paid postage and tax sit in that total. Offering free shipping drops that slice and puts the label on leftover instead — the cheaper path depends on the hammer and the label, which is why the page compares both.
Does Whatnot take 8% on a $2,400 graded card?
Not on the published US TCG / comics / sports / toys row. That row commissions 8% only up to $1,500 of the hammer; the portion above is 0%. A $2,400 lot is $120 of commission, not $192. The cap is labelled limited-time on Whatnot's help page — confirm it on the lot before you treat it as permanent.
Is my data uploaded anywhere?
No. Parsing and arithmetic happen entirely in your browser. Hammers, costs, and leftovers are never uploaded. The optional usage counter records only which features were used and the day, never any of your numbers.
Have your whole order history instead of one lot? The Whatnot sales report analyzer reads your orders CSV and shows profit per show and category — nothing uploaded.