About

What is SellKitHub?

SellKitHub is a collection of free fee and profit calculators for people who sell online — on Etsy, eBay, Amazon, Shopify, or through PayPal and Stripe. Each tool answers one question well: type your numbers, see every fee broken out line by line, and see the profit that is actually left.

How we handle fee data

Marketplace and payment fees change often, and stale fee data is worse than no fee data. Every rate on SellKitHub lives in one central fee file. Each entry records the rate, the official platform source it came from, and explanatory notes — including the cases where a platform's full schedule is too detailed for a simple calculator, in which case the page labels its figures as representative examples and tells you where to verify the exact number. Fee data on this site was last updated in Oct 2026.

How your data is handled

Every calculation happens locally in your browser with plain JavaScript. The numbers you type are processed on your own device and are never sent to our servers, stored, or shared — there are no accounts. To keep SellKitHub free we may show ads: advertising partners, including Google, may use cookies or device identifiers to serve and measure ads, including personalized ads where you have consented. Read our privacy policy for the full details.

Built for accuracy — within stated limits

Each calculator shows the formula it uses in its “How it works” section and a worked example you can check by hand. Results are estimates based on the numbers you enter and the fee schedule stated on the page — a starting point for pricing decisions, not professional financial or tax advice. Always verify against the platform's current official fee schedule before committing to inventory or prices.

Corrections

Found a fee that has changed, or a mistake in a formula or worked example? Contact us with the page name and the official source. Fee accuracy is the whole point of this site, so confirmed corrections are made promptly and the fee file's updated date is revised.

Get in touch

Found a bug, want a calculator for another platform, or have feedback? Contact us — we read every message.