The eBay Fee Calculator for Chrome is a free 3Dsellers browser extension that works out what eBay will take from a sale and what you will keep, on the listing you already have open. Open an eBay item page, click the extension icon, and the calculator appears in a toolbar panel with the item's price, the shipping the seller charges, the title, the photo, the eBay site and the eBay category already filled in. Add what the item cost you, and it shows the fees, your break-even price, your expenses and your profit, recalculating on every keystroke.

Watch the walkthrough, then use the sections below as a reference:

In this article:

The eBay Fee Calculator for Chrome is one toolbar popup and nothing else - no options page, no new tab, no context menu, and, the part that matters most, no content scripts. It injects nothing when an eBay page loads, so it never modifies, styles or slows down the page you are looking at; when you click the icon it injects one read-only function that reads a handful of values and hands them back to the panel. Everything else happens inside the 600-pixel-wide panel itself.

What the eBay Fee Calculator extension does:

It reads one public eBay page and nothing else: it never signs in to eBay, never touches your account or your real payouts, and never changes the listing it is reading. Limits has the full list.

The eBay Fee Calculator for Chrome is published free on the Chrome Web Store by 3Dsellers, under Workflow & Planning, and lives in your browser toolbar once installed.

The panel is a toolbar popup, so it sits over the eBay page rather than inside it. Below it is open on a live eBay item page: the item price, the shipping, the title, the photo and the category all came from the listing underneath, which is itself untouched.

The eBay Fee Calculator extension fills itself in on eBay item pages only. It checks two things about the tab you are on: that the hostname matches ebay.* (so www.ebay.com, www.ebay.co.uk, www.ebay.de and the rest all qualify), and that the path contains /itm/ - either www.ebay.com/itm/178464688487 or the longer /itm/<slug>/<item number> form.

Nothing else triggers the auto-fill. eBay search results, category and browse pages, a seller's eBay Store, My eBay, the Watchlist, your purchase history, Seller Hub (including the Active and Sold grids) and the listing form you draft in all do not fill the calculator in.

On any of those pages - and on any non-eBay tab - the panel still opens and works as a manual calculator: the item column shows the placeholder art and the bottom row reads "Fill data automatically: Go to an eBay item and open the extension." That line is how you tell "this is not an item page" from "the extension is broken".

On an eBay item page the eBay Fee Calculator for Chrome reads six things and prints each of them back at you, so you can see exactly what it used:

Below, the panel has just opened and nothing has been typed. The Item price of 425 (1) and the Shipping price of 125 (2) were read from the listing, and the item title (3) and photo (4) are the listing's own. The three cost fields are still empty - those are yours.

The eBay Fee Calculator extension matches the item's breadcrumb trail against its own fee table, taking the deepest match - so a sub-category beats its parent. On the bass guitar used throughout this article the breadcrumb is Books, Movies & Music › Musical Instruments & Gear › Guitars & Basses › Bass Guitars, so the calculator selects Guitars & Basses and labels it (auto) (1):

Lower down, the panel restates it in words: "Read from the page: Bass Guitars. Change any value to recalculate."

Three numbers, all of them yours, all under the Pricing Information heading. The extension cannot know any of them from the listing, and until you enter one the profit figure is just the payout.

The Item price and Shipping price fields above them are editable too, so you can overwrite either to model a different price. Below, the three cost fields have been filled in: item costs 240.00 (1), shipping costs 96.00 (2) and other costs 12.00 (3).

The eBay Fees: group is where the fee itself is decided. The eBay Fee Calculator for Chrome sets the first three from the page and leaves the rest at their defaults, so in most cases you change nothing - but each one is yours to override.

Below, the two controls that move the number most are marked - the Category (1), which sets the rate, and Top Rated Plus listing (-10%) (2), which discounts it. Everything between them is at its default here.

The middle column of the eBay Fee Calculator for Chrome holds four result tiles, each with a question-mark tooltip, all four recalculated on every keystroke: the fees, the price you must not sell below, what the sale costs you, and what is left.

The margin under Profit is your profit as a percentage of the item price plus the shipping you charge. Sales tax is left out of that revenue figure, because it is collected for the tax authority rather than earned by you - even though eBay does charge its fee on it.

This is the sale used in the video, calculated by the extension on the live listing: a used Guild EB-0 4-string electric bass on eBay.com at 425.00 USD with 125.00 USD shipping, in Guitars & Basses, sold by a no-store seller to a domestic buyer with no promoted ads and no sales tax. The extension read the 425 and the 125 off the listing; the costs were typed in - item 240.00, shipping 96.00, other 12.00. That produces:

Hover the question mark on the Fees tile and the tooltip becomes the per-line breakdown. On this sale it reads:

The Profit tooltip is the same ladder for the money, from the sale down to what you keep:

This is the reason to install the extension rather than type numbers into a calculator. Guitars & Basses is charged at 6.7% on eBay.com; Most categories is charged at 13.6%. Overriding the Category (1) to Most categories on this same sale takes the Fees tile (2) from 37.25 USD to 75.20 USD and the Profit tile (3) from 164.75 USD down to 126.80 USD, at a 23.1% margin instead of 30.0%.

Ticking Top Rated Plus listing (-10%) on this same sale takes the fees from 37.25 USD to 33.56 USD and lifts the profit from 164.75 USD to 168.43 USD, a 30.6% margin.

The eBay Fee Calculator for Chrome carries its own fee tables - per-category rates, seller types, per-order fees and international fees - for five sites: eBay.com (US), eBay.co.uk (UK), eBay.ca (Canada), eBay.com.au (Australia) and eBay.de (Germany). The site is chosen from the item page's hostname, so an eBay.co.uk listing loads the UK table and UK seller types without you touching the dropdown.

Any other eBay site - eBay.it, eBay.fr, eBay.com.my and the rest - falls back to Other eBay site (manual rate): the category list collapses to a single Manual rate entry that starts at a 13% placeholder rather than that site's real fee, and the Fee override (%) placeholder changes from auto to site rate to prompt you for the right percentage. Everything else in the panel works as it does on a supported site.

Because a browser extension cannot read a page without being allowed to. The eBay Fee Calculator for Chrome asks for the smallest set that makes reading the listing possible - three permissions plus host access to eBay:

The extension also allows pages on www.3dsellers.com, and no other site, to send it a message so a 3Dsellers page can hand it a lookup. Your numbers never leave the browser: the fee tables ship inside the extension, and only anonymous usage events, error reports and text you type into Report a bug or Suggest a feature are sent anywhere.

3Dsellers publishes the fee calculation in two places, and they are good at different things: the eBay Fee Calculator for Chrome reads a listing that already exists, while the web eBay Fee Calculator models a listing you have not made yet. Neither replaces the other.

The eBay Fee Calculator for Chrome models one sale from one public page. It will not:

The eBay Fee Calculator extension fills in on eBay item pages only, and it says so when it cannot: the bottom row reads "Fill data automatically: Go to an eBay item and open the extension." Check the address bar - the path has to contain /itm/. Search results, a store, My eBay, Seller Hub and the listing form look like listings but are not item pages.

The eBay Fee Calculator extension keeps the last price and shipping it read, so the panel is not blank on a non-eBay tab - and those older numbers are what you see if you opened it away from an item page. Reopen it on the item page you want: both fields are overwritten and the bottom row changes to "Read from the page: …".

The eBay Fee Calculator extension takes the category from the listing's own breadcrumb, so if the seller filed the item oddly the calculator inherits that. Override it in the Category dropdown - which clears the (auto) badge until you reopen the panel on the item page.

It is not meant to: the line under the Fees tile is the effective rate on the whole sale, which includes the fixed per-order fee and any ads or international fee. Your category's final value fee rate is on the "Final value fee" line of the Fees tooltip - see what the tiles mean.

That banner appears when Chrome is still running an older build without the permissions the current calculator needs, so it can neither read the page nor remember your inputs. The banner names the fix: open chrome://extensions, remove eBay Fee Calculator and add it again from the Chrome Web Store. Figures you type still calculate meanwhile.

The eBay Fee Calculator extension has full fee tables for eBay.com, eBay.co.uk, eBay.ca, eBay.com.au and eBay.de only. On any other eBay site it selects Other eBay site (manual rate), whose single Manual rate starts at a 13% placeholder - type that site's real percentage into Fee override (%) and the rest of the panel is accurate again.

Yes - the eBay Fee Calculator for Chrome is completely free. There is no 3Dsellers account, no sign-in, no card and no trial: you add it from the Chrome Web Store and click the icon on an eBay listing.

No - the eBay Fee Calculator extension declares no content scripts, so nothing runs when an eBay page loads and nothing is added to the page. The only code that touches it is one read-only function, injected when you click the icon, which reads a few values and hands them to the panel.

No - the eBay Fee Calculator extension calculates entirely in your browser, so your prices, your costs and the item's details are not sent anywhere. Only anonymous usage events, error reports and text you type into Report a bug or Suggest a feature leave the browser. No account is needed.

The rates are taken from eBay's own fee pages and stamped with the date they were captured, printed along the bottom of the panel - for example "eBay.com (US) rates from eBay's fee pages, as of 2026-09-06". Because eBay changes fees periodically, read the result as an accurate estimate for that date.

Because the category was changed by hand. The eBay Fee Calculator extension clears the (auto) badge as soon as you pick a category yourself, and re-selecting the detected category does not restore it. Close the panel and reopen it on the item page: the extension reads the breadcrumb again and the badge comes back.