Privacy
Your numbers
The prices, costs and fees you enter are calculated in your browser. They are not sent to a server. Each calculator keeps your last entries, currency label, target margin and monthly order count in this browser’s local storage (keys seller-margin-lab:general, seller-margin-lab:amazon, seller-margin-lab:etsy and seller-margin-lab:landed) so they are there when you come back. Reset example removes the saved entries for that calculator; clearing this site’s data in your browser removes all of them. Copy summary uses your device’s clipboard.
Optional account
The calculators work without an account. If you choose Sign in, the sign-in panel sends your email address to Supabase, the account service this site uses, so it can email you a sign-in link; once you are signed in, it stores a session in your browser and reads your account’s subscription status from Supabase. Your calculator entries are not sent with it. If you never use Sign in, nothing is sent to Supabase.
Analytics
This site includes a statistics script that is only enabled after consent, but it does not currently run on this domain and collects no statistics.
Hosting
The site is hosted on Cloudflare, which, like any web host, processes technical request data such as IP address and browser type to deliver the pages.
Last updated: 19 October 2026