Ecommerce seller economics

Ecommerce Seller Calculators

Calculate marketplace fees, profit, pricing, advertising break-even points, ROAS, ACoS, and seller margins with tools built specifically for ecommerce operators.

Review methodology

Marketplace sections

Etsy

Estimate Etsy seller fees, pricing, profit, margins, and product-level economics with source-backed SellerFormulas tools.

Amazon

Estimate Amazon FBA fees, calculate advertising efficiency, plan break-even ACoS, and model product-level profit with transparent US seller tools.

eBay

Estimate eBay selling fees and product-level profit for US sellers with transparent fee-base and seller-cost assumptions.

TikTok Shop

Estimate TikTok Shop US seller referral fees and order-level profit with transparent source tracking.

Advertising

Plan ROAS, ACoS, break-even ad spend, contribution margin, and ecommerce advertising economics.

Current fee sources

Fee data is designed to be stored centrally with source URLs, effective dates, and last-verified dates.

Transparent formulas

Calculator logic will live in reusable utilities rather than being scattered through page components.

Seller-focused calculations

The site stays focused on marketplace fees, margins, pricing, ROAS, ACoS, and unit economics.