- 8 free tools
- 4 marketplaces covered
- 0 sign-ups or paywalls
- Oct 16, 2026 latest fee check
Why this exists
Every marketplace takes its cut before the money reaches you: a referral fee here, a payment fee there, a fixed charge per order that quietly eats cheap items alive. The platforms publish these numbers, but they are spread across long help pages and change several times a year.
MarginToolkit puts them in one place. Pick where you sell, type your price and costs, and see your real profit, margin and break-even price in seconds. No spreadsheet, no account, no guesswork.
How we keep the numbers honest
- 1 Read the source Every fee comes from the platform's own fee page or rate card, never from a blog post or a forum thread.
- 2 Test the math Each calculator has automated tests that check its results against worked examples from those pages.
- 3 Show the date Every tool says when its numbers were last checked, so you know how fresh they are.
Where the current numbers come from
- Amazon US fee schedules, checked Oct 16, 2026
- Shopify shopify.com/pricing, checked Oct 16, 2026
- Etsy Fee and payments policies, checked Oct 16, 2026
- eBay Selling fees help page, checked Oct 16, 2026
- USPS, UPS, FedEx Dimensional weight rules, checked Oct 16, 2026
Who builds it
Rehman Javed
Software engineer and online seller
I sell on Amazon and run my own Shopify stores, so I pay these fees every week. I built MarginToolkit because I wanted fast, trustworthy answers to the questions I kept asking myself: what will this cost me to sell, and is the price high enough?
By day I'm a software engineer building web apps, and I also build and fix Shopify stores for other sellers.
What you can count on
- Free, for good No trials, no limits, no "upgrade to see your profit". Ads pay for the site.
- Private by design Calculators run in your browser. What you type never reaches our servers.
- Honest about limits Each tool says what it includes and what it leaves out, like storage or peak fees.
- Built for real decisions Break-even prices, target margins and "what if" answers, not just a fee total.