About the project

Why it exists

There are plenty of fee calculators around and almost all of them share the same flaw: they tell you what the platform takes but not what you keep. They skip the tax, never ask about real shipping cost, assume a universal fee percentage, assume a single country, or never mention advertising. The result is a reassuring number that cannot support a single decision.

This project tries the opposite: ask for every input that matters, even if that means more fields, and be explicit when something cannot be known. If Amazon's fulfillment fee depends on your product, the tool asks for it instead of inventing it. If Etsy's processing percentage changes with your country, there are eight markets instead of one.

The principles

• Free and no sign-up. No accounts, no usage limits, no paid tier.
• The maths runs in your browser. Your prices, costs and margins never leave your device.
• Formulas in the open. Every calculator publishes its formulas so you can reproduce them by hand.
• Fees editable, dated and status-marked. Defaults carry a source, a review date and a verification status, and you can always override them.
• Nothing invented. No unsourced statistics, testimonials, user counts or benchmark figures pulled out of the air. And when we could not verify something, we say so.
• Explicit limits. Where an estimate has a boundary, it is written down.
• Language and market independent. Because plenty of Spanish-speaking sellers sell into the US, and plenty of English-speaking ones sell into the eurozone.

Who it is for

Anyone selling online who wants to know what they actually earn: own stores on Shopify, WooCommerce or PrestaShop, Etsy and Amazon FBA sellers, freelance marketers running other people's accounts, agencies that need to justify a ROAS target with numbers, and anyone starting out who wants to understand the cost structure before setting prices.

How it is funded

The intention is to fund the project with advertising, not by charging for the tools. In this version the ad slots are reserved but empty: no third-party script is loaded and there is no real advertising.

When they are switched on, it will be under these rules: never inside the form, never between the calculate button and the results, never on the legal or contact pages, no pop-ups, and with the height reserved so the page does not jump. And before activating anything that requires consent, a certified consent management platform will be installed.

Independence

!Independent project. Not affiliated with, sponsored by or endorsed by Etsy, Amazon, Shopify, WooCommerce or Google. Those platform names appear purely to identify whose fee structure is being discussed.

Current status

Profyza is published and operational on its permanent domain. The current service includes:

• 20 calculators working in both languages and all eight markets.
• 9 guides and 3 worked case studies published.
• The calculation engine passes its full test suite (you can run it here).
• The owner's legal details are already in the legal notice.
• Search engine indexing is already active.
• Advertising and analytics are wired up but still switched off.
• Some fees are flagged as pending verification on the sources page.

Editorial curation explains assumptions, sources and limitations. An automated suite verifies the maths with calculations independent of the engine. That is not human or professional review: the content has not been reviewed by an economist, accountant or adviser, and every estimate still depends on the quality of the inputs supplied.

How to help

The most useful thing you can do is report an error: an out-of-date fee, a formula that does not match your real invoice, a case the calculator does not cover. Write via the contact page.

What comes next

The published product keeps improving; it is not considered finished forever. No promises on dates, but these are the pieces that make sense next: closing out the fees still pending verification, a break-even volume calculator that brings fixed costs together with contribution margin, side-by-side scenario comparison, and more interface languages for the markets already supported.