Shopify vs Amazon Margin Calculator
Enter one product's price and costs, then see side by side what you keep per unit and per month on a Shopify store and on Amazon with FBA. Every fee is an editable input with its official fee page beside it, because fees change and differ by category and size. The tool shows profit per unit, margin, monthly profit at the volume you choose, the break-even volume on each channel, and where the two cross. It is for sellers deciding where to list a product first. Everything runs in your browser; nothing is uploaded, stored or sent.
Fee defaults marked confirmed 2026-10-23 were read on the official page that day. All others are examples, check the current fee page.
How it works
For each channel the tool starts from your price and subtracts the costs you enter: product cost, shipping or the FBA fee, storage, payment processing (Shopify) or the referral percentage (Amazon), and advertising as a percentage of sales. Profit per unit is what remains per unit ordered, and margin is that profit divided by the selling price. Monthly profit multiplies unit profit by your volume and then subtracts the fixed monthly costs: the Shopify plan plus apps, and the Amazon seller plan.
Break-even volume is fixed monthly cost divided by unit profit, rounded up. If unit profit is zero or negative the tool shows that no volume breaks even. The crossover volume is the monthly volume at which both channels earn the same profit, which matters when one channel has higher unit profit but higher fixed cost.
Returns
A returned unit is modeled as lost revenue with the goods written off. Shopify card fees are not refunded; the Amazon referral fee is assumed refunded. Both are simplifications, so use your own return rate and treat the result as an estimate.
What it does not model
- Demand. Amazon brings shoppers who are already searching. A Shopify store must earn traffic, usually through ads, content or email. The ad percentages here are your guess at that cost, and the biggest swing factor.
- Customer data. On Shopify you keep customer emails for repeat sales. On Amazon you largely do not, so lifetime value differs.
- Category-specific referral tiers, size and weight fee bands, aged-inventory and long-term storage charges, inbound placement fees, removal fees, sales tax, currency, taxes, chargebacks, disputes, Shopify Payments availability by country, and third-party payment gateways.
- Multi-unit orders, shipping charged to customers, discounts and coupons.
Honest framing
A margin comparison favors whichever channel you give the cheaper ad percentage, so test a range rather than one number. Many brands use both: Amazon for discovery, Shopify for repeat customers. This tool does not recommend either one.
Disclosure: the author runs an Amazon advertising agency and builds Shopify apps, so has business interests in both channels. See the disclosure. Nothing is promoted in this tool.
Data last verified 2026-10-23. Prices, hours and rules change; confirm fees, limits and program terms with the official source before you rely on a number.
Sources
Related guides
Frequently asked questions
Are the default fees current?
Only some. On 23 October 2026 we read the Shopify pricing page (Basic plan $39 per month on monthly billing, 2.9% plus 30 cents online card rate) and the Amazon selling-plan page (Professional plan $39.99 per month, 15% default referral fee). Shipping, FBA fee, storage, apps and ad percentages are examples we could not confirm for your product. Check each fee page linked beside the field.
Why does Amazon often look more expensive per unit?
Amazon bundles fulfilment, a referral percentage and usually heavier advertising into the unit cost, while Shopify has lower per-sale fees but a fixed monthly cost and your own traffic cost. Which wins depends on your ad percentages, which the tool lets you set separately for each channel.
What is the break-even volume?
It is the number of units per month at which that channel's unit profit covers its fixed monthly costs (plan plus apps). Below it you lose money on that channel; the tool shows none if the unit profit is zero or negative. A crossover volume shows where the two channels earn the same monthly profit.
How are returns handled?
Returned orders are treated as refunded revenue with no resale of the goods, which is conservative. Payment processing fees are not refunded, and the Amazon referral fee is assumed refunded on returned units. Real policies differ, so adjust the returns percentage to match your results.
Does this say which channel I should use?
No. Amazon brings built-in demand and Shopify brings customer data and control, neither of which a margin calculator can price. Use it to see how sensitive your profit is to fees and ad spend, then read the guide.