Channel Margin Calculator

Estimate your per-unit contribution margin across Etsy, Amazon FBA, Amazon FBM, eBay, and Shopify for up to 5 SKUs at once — free, no email required, no catch. Real math, not a lead-gen placeholder: this runs the same formulas we use in our own commerce-economics work.

Fee data below observed 2026-09-08 from each platform's own published fee page (see Sources). Not guaranteed current — marketplace fees change over time.

Add a SKU (up to 5 on this free calculator)

SKU / product name *required

Sale price (USD) *required

Cost of goods (USD) *required

Your outbound shipping (USD) *required

Channel fee settings

US region, general/most-common-category representative rates, Shopify Basic plan. Etsy, Amazon's referral-fee range, and eBay's fee schedule are from each platform's own published page (see Sources). Amazon FBA's fulfillment fee has no default — it varies by size/weight/price band and requires your own Seller Central Revenue Calculator figure; you must enter it yourself, or the FBA column stays UNKNOWN rather than guessing.

Etsy

Listing fee (USD)

Transaction fee (%)

Payment processing (%)

Payment processing fixed (USD)

Amazon FBA

Referral fee (%)

Referral fee minimum (USD)

Fulfillment fee (USD) *required, no default

⚠ Amazon's referral fee really ranges ~5%-45% by category (15% here is representative, not your exact rate). The FBA fulfillment fee has no default value on this page — leave it blank and the FBA column shows UNKNOWN, it is never assumed to be any particular number.

Amazon FBM

Referral fee (%)

Referral fee minimum (USD)

eBay

Final value fee (%)

Per-order fee, ≤$10 (USD)

Per-order fee, >$10 (USD)

Shopify + card payments

Card processing (%)

Card processing fixed (USD)

2.9% + $0.30 is Shopify's Basic-plan online rate as a moderate-confidence starting point (not independently fetch-verified this pass) — edit to match your real plan.

Sources

Etsy seller fees: etsy.com/legal/fees and Etsy's "Fee Basics" help article.
Amazon referral fee structure: sell.amazon.com/pricing (real range ~5%-45% by category). Amazon's FBA fulfillment-fee table requires a logged-in Seller Central account — not independently fetched for this page, which is exactly why this page never defaults it.
eBay seller fees: ebay.com/help/selling/fees-credits-invoices/selling-fees.
Shopify card-processing rate: aggregated from shopify.com/pricing, moderate confidence only (that page renders pricing by region/locale; confirm your own rate there).

Scope and limitations

This is an estimated per-unit contribution margin (price minus COGS minus your fulfillment cost minus modeled channel fees) — not the amount a platform actually pays out (a real payout subtracts only platform fees, not your COGS/fulfillment), and not full profit (order volume, returns, ad spend, taxes, currency conversion, and fixed monthly platform costs are excluded). Assumes the same list price on every channel. Not accounting, tax, or business advice. When two or more channels are within $0.005 of each other they are reported as tied, not arbitrarily picked. This free calculator is capped at 5 SKUs at a time; unlimited batch scoring (many SKUs via CSV/API) is part of our paid Commerce Economics tooling.

Want this for your whole catalog?

This free page is capped at 5 SKUs and is meant to show the real math, not replace a working tool for a full catalog. If you sell dozens (or hundreds) of SKUs across channels and want batch scoring, editable fee schedules, and export, email us with a rough sense of your catalog size and channels and we'll scope it.

Email hello@tsaielectro.com →

There is no separate paid Starter product live yet — this is a direct, attributable interest contact, not a checkout link.