How eBay fees are worked out
Most US sales carry two fees. The final value fee is 13.6% of the total amount of the sale for most categories, charged per item on the first $7,500 and at 2.35% on any part of a single item's sale above $7,500. The per-order fee is a flat $0.30 if the order total is $10 or less and $0.40 above that. If you promote the listing and the ad leads to the sale, the Promoted Listings General fee is your chosen ad rate times the same total. Sellers without a store subscription also pay an insertion fee after their free monthly listings run out, which this calculator leaves out.
Why sales tax matters
The total amount of the sale includes the item price, the shipping you charge, and the sales tax eBay collects from the buyer. eBay passes the tax on to the state, so you never receive it, but you still pay the final value fee and any ad fee on it. That is why the calculator asks for the buyer's tax rate: at 7% tax a $30 sale is charged fees on $32.10. Use the rate for where most of your buyers live, or 0 if you only want a rough figure.
What you actually keep
You receive the item price and shipping you charged, minus eBay's fees. If you buy the shipping label through eBay, its cost is taken from the same payout, so enter it to see what lands in your bank. Add your cost of goods to see profit per sale. The fee as a percentage is shown against price plus shipping, which is the money you charged, so it is a little higher than the headline rate once tax and the per-order fee are added.
Categories with different rates
Books, DVDs, movies and music, and some collectibles carry a higher rate, while some, such as guitars and heavy equipment, carry lower or tiered rates. Store subscribers get slightly lower rates in many categories. Edit the final value fee to match your category and status; the per-order fee and the 2.35% rate above $7,500 stay the same.