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How our calculators work

Every Bussnizz calculator uses each platform’s own published fees, shows its formula, and shows the date its rates were last reviewed. Results are estimates, not a statement from the platform.

The basic formula

Most seller calculators follow the same steps:

  1. Order total = sale price + shipping you charge the buyer.
  2. Platform fees = the marketplace’s percentage and fixed fees, worked out on the amounts that platform charges on (for example, Etsy and eBay charge on shipping too).
  3. Payment processing = the processor’s percentage + fixed fee, where the platform charges it separately.
  4. Net profit = order total − item cost − shipping label − platform fees − payment fees − ads and other costs you enter.
  5. Profit margin = net profit ÷ order total × 100.

Each calculator prints its own exact formula and a worked example on the page, so you can check the math by hand.

Where our fee data comes from

We only use each company’s own published fee pages:

We don’t use third-party fee summaries, because they go out of date.

How often fees are reviewed

We check fee schedules against the platforms’ pages regularly, and as soon as a platform announces a change. Each calculator shows its “last reviewed” date, and every rate can be edited under Assumptions and rates if your account is different.

How the fee change log works

When a rate changes, we update the single fee file every calculator reads from, re-run the automated tests, and add a dated entry to the fee change log. Affected guides are updated and show a new “last reviewed” date.

Why results are estimates

Your real charges can differ because of category rules, promotions, taxes, currency conversion, refunds, and account-specific terms. Always confirm with your seller statement. See our disclaimer.

Common questions

Are the calculators free? Yes. Every calculator and guide is free, with no account and no usage limit.

Do you store what I type? No. Calculator inputs stay in your browser. Product photos you compress are processed on your device and never uploaded.

Can I share a calculation? Yes. The Share button copies a link with your numbers, so anyone who opens it sees the same result.

I found a fee that changed. How do I tell you? Use the contact page and include a link to the platform’s fee page. We check every report.

Do affiliate partnerships change results? Never. Calculators and rankings are neutral. See the affiliate disclosure.