One calculator, every channel

Profit Margin Calculator — the number after the fees

Pick your platform below. Each page models that channel's real fee stack — Amazon FBA's fulfilment and storage, FBM's shipping and labor, or Shopify / eBay / Etsy's own costs — so the net margin is honest.

📦

Amazon FBA

FBA fulfilment fee, storage and referral — for inventory Amazon picks, packs and ships.

Calculator
🚚

Amazon FBM

Self-fulfilled: carrier shipping, packaging, pick & pack labor and return handling.

Calculator
🛍️

Shopify

No referral fee — just the payment fee, your shipping and handling.

Calculator
🔨

eBay

Final-value fee plus managed-payments fee, your shipping and handling.

Calculator
🎨

Etsy

Etsy's 6.5% fee plus payment fee, your shipping and handling.

Calculator
⚙️

Custom

Set your own referral and payment percentages for any other marketplace.

Calculator

Why a separate page per platform?

A marketplace's profit is decided by its fee stack — and those stacks barely overlap.

Amazon FBA folds fulfilment into one size-and-weight fee plus monthly storage (which spikes roughly 3–4× in Q4). Amazon FBM has no FBA fee at all — instead you eat carrier shipping to the buyer, packaging, pick & pack labor, and return handling. Shopify charges no referral fee but a payment fee; eBay and Etsy each have their own fee blends.

One generic calculator can't represent all of that without lying somewhere. So each channel gets its own tailored calculator — same engine, correct cost lines, copy that speaks to how that platform actually bills you. Switch any time with the platform switcher at the top of every page.

What every version shares

  • True net margin — (price − every per-unit cost) ÷ price, including COGS, shipping, fulfilment, referral/payment fees, import duty/landed cost, PPC and a returns allowance.
  • Reverse price — enter a target net margin and get the price that delivers it, accounting for fees that scale with price.
  • Tool-chain prefill — Import Duty sends a per-unit landed cost and Volumetric Weight sends per-unit shipping, both prefilling the matching fields.
  • Free, private — no sign-up, everything runs in your browser.

Profit Margin — common questions

Which page should I use?
If you send inventory to Amazon, use Amazon FBA. If you ship orders yourself, use Amazon FBM. For your own storefront use Shopify; for marketplace listings use eBay or Etsy. Each models that channel's real fees.
Is it free and private?
Yes — 100% free, no sign-up, and the numbers you enter never leave your device.
Can I use data from the other tools?
Yes. Volumetric Weight can send a per-unit shipping estimate and Import Duty can send a per-unit landed cost — both prefill the matching fields on each calculator.
How accurate are the fee presets?
They're indicative published ranges — Amazon referral fees by category (8–20%), FBA size-tier fees, Shopify's ~2.9% + $0.30 payment fee, eBay/Etsy defaults. Edit any field to match your actual plan.

Worked example

One $29.99 sale, run through the Amazon FBA calculator.

You sell a toy at $29.99, product cost $8.00. The FBA preset takes the 15% toy referral fee ($4.50), a small-standard FBA fulfillment fee (≈ $3.50) and a storage estimate ($0.50):

Net per unit = $29.99 − $8.00 − $4.50 − $3.50 − $0.50 = $13.49 (45% net margin).

Change any preset and the number re-computes instantly — that is the point: the fee stacks differ per channel, so each platform page carries its own defaults.

Sources & methodology

How this calculator was built and where the reference figures come from.

Last verified: August 2026 · Confidence: High

Primary source: Amazon — Selling fees

Reference rates are editable and drawn from public policy reports; confirm the exact figures with the relevant marketplace seller agreement and the relevant authority before relying on them.