Methodology

This page explains how our calculators work and where our fee data comes from, so you can trust — and check — the numbers.

How we calculate net profit

For each sale we take your gross revenue (item price plus the shipping you charge), subtract the platform fees, then subtract your own costs (item cost plus your shipping cost). What remains is your net profit, and your margin is net profit divided by gross revenue.

Where our fee data comes from

Each platform fee comes from its official published fee pages. Every calculator records the rate it uses and a last-updated date. We use the most common standard rate for each platform (usually US, standard category).

Why your exact fee may differ

• Fees vary by category, country, subscription plan, and seller level.
• Some platforms add optional costs (ads, fulfillment, offsite ads) that we do not include by default.
• Platforms change their fees, sometimes with little notice.

Always confirm the exact rate with the platform before relying on a result. Our numbers are careful estimates, not a guarantee.

Updates

We review platform fees periodically and update the last-updated date on each calculator when rates change. Spotted an outdated rate? Let us know.