Independent calculator hub

About Seller Math Hub

Seller Math Hub helps ecommerce sellers model profit, pricing, fees, and ad break-even scenarios with transparent formulas and editable assumptions.

Why this site exists

Revenue can look healthy while fees, fulfillment, returns, advertising, and overhead quietly consume the order. Seller Math Hub turns those cost layers into visible inputs, shows the formula behind each result, and lets sellers change assumptions instead of accepting a black-box answer.

How the calculators are maintained

The Seller Math Hub Editorial Team reviews formula logic, rate-sensitive assumptions, official source links, and calculator limitations. Platform-specific defaults are recorded in the public rate and source ledger, with material changes noted in the rate changelog. Automated tests cover the core formulas and site integrity.

Defaults are planning assumptions, not universal rates. Platform charges can vary by country, account, plan, payment method, service, product category, tax treatment, and date. Every seller should compare an estimate with current official documentation and an actual payout statement.

Editorial principles

• Show the formula and important assumptions.
• Link fee-sensitive claims to primary, official sources.
• State dates, geography, uncertainty, and exclusions.
• Never let affiliate or commercial relationships alter calculator math.
• Correct meaningful errors and record material rate changes.

The site is independent. It is not affiliated with, endorsed by, or sponsored by Etsy, Shopify, Stripe, PayPal, Google, or any referenced platform unless explicitly stated.

Calculator outputs are estimates only. They are not tax, legal, financial, accounting, or business advice.

Questions, correction requests, and source suggestions are welcome through the contact page.