About SellerTools Online

SellerTools Online is a collection of free calculators built for Amazon, eBay, and Etsy sellers. Every tool is designed around real seller workflows — calculating true FBA profit, determining size tiers before ordering inventory, and pricing products to hit a specific margin target.

Who built this?

I've been selling on Amazon North America since 2019. I started building these tools because I got frustrated with the available options — either they required a login, showed ads, or got the fee math wrong. This site is my attempt to fix that.

All calculations run entirely in your browser. We don't store your numbers, we don't sell your data, and there's no account required.

How are the tools kept accurate?

Amazon, eBay, and Etsy update their fee schedules periodically. I update the calculators whenever fee changes are announced. If you notice an error, please contact me.

Can I embed these tools?

Yes — every tool includes a free embed code. Copy the iframe snippet and paste it into your blog, seller course site, or any webpage. See the embed example page for instructions.