Ecommerce Profit Calculator — Methodology

Step-by-step calculation

Find true profit per unit after platform fees, shipping, advertising, and VAT — across Amazon, Etsy, eBay, and Shopify.

1. 1

   Pick your platform

   Click Amazon FBA, Etsy, eBay, Shopify, or Custom — the platform fee % pre-fills accordingly.

2. 2

   Enter selling price and product cost

   Your listing price and the landed cost of the product to you (including shipping into your warehouse).

3. 3

   Add shipping and ad spend per sale

   Outbound shipping cost (if you cover it) and the advertising cost attributable to each sale.

4. 4

   Set the VAT rate (optional, UK/SA)

   VAT is removed from the gross price for VAT-registered sellers in UK and SA.

5. 5

   Read net profit and net margin per unit

   The result shows what actually reaches your bank after every deduction.

Assumptions and overrides

Platform fee defaults: Amazon FBA 15%, Etsy 6.5%, eBay 13%, Shopify 2.9%. Headline rates only — your actual fees may include category-specific premiums or volume discounts. Check your platform's seller dashboard for the exact split.

Every region default on the calculator is editable. If your effective rate, fee, or threshold differs from the headline figure shown, type your own number into the field — the calculator recomputes instantly without leaving this page.

Primary sources

Region-tagged primary sources for the default rates, thresholds, and benchmarks used in this calculator.

• USAIRS — Sales and Use Tax (US varies by state)
• UKGOV.UK — VAT rates (UK standard 20%)
• SASARS — Value-Added Tax (SA standard 15%)

Review cadence and corrections

This methodology and the underlying rate defaults are reviewed at least annually, and immediately following any change to the headline rate from IRS, HMRC, or SARS. Every substantive update is recorded on the public changelog. Spotted an error? See the corrections policy for how to report it.

See the full editorial policy for the standards every page on BusCalcTools is held to.