Amazon FBA calculator for the UK and Europe: real profit and margin
Free Amazon FBA calculator for the UK and Europe: VAT, referral and FBA fees, storage, ads and returns. Real profit, margin, ROI and break-even TACoS.
Gazi El Halabi · · Updated
In short
Enter the selling price, your product and shipping costs, Amazon’s referral and FBA fees, your ad spend and return rate. The calculator removes VAT and every cost to show what each sale really leaves: profit per unit, net margin, ROI and the most you can spend on ads before you lose money. It runs in your browser; nothing is sent or stored.
Example figures: replace them with your own.
Profit per unit
5.00 £
Net margin
20%
ROI on stock
61.8%
Break-even ad spend
26.7% of sales
Strong margin: room to invest in growth.
- VAT5.00 £
- Product + shipping in8.10 £
- Amazon fees8.65 £
- Advertising3.00 £
- Returns0.24 £
- Profit5.00 £
Net revenue (ex VAT): 24.99 £
VAT on Amazon’s fees is not included (recoverable when VAT-registered). Long-term storage, removals and currency conversion are not covered.
Why revenue is the wrong number
A €29.99 sale is not €29.99 of income. VAT comes off first, then the product and the shipping to Amazon, then Amazon’s referral and fulfilment fees, then advertising and returns. What is left is often a fraction of the price, and a product can grow its sales every month while losing money on each one.
How it calculates
| Line | Formula |
|---|---|
| Net revenue | Price ÷ (1 + VAT rate) |
| Referral fee | Price × referral % (Amazon applies it to the VAT-inclusive price) |
| Advertising | Price × TACoS (ad spend as a share of total sales) |
| Returns | Return rate × cost per return |
| Profit | Net revenue − product − shipping to Amazon − Amazon fees − advertising − returns |
| Net margin | Profit ÷ net revenue |
| ROI | Profit ÷ (product cost + shipping to Amazon) |
| Break-even ad spend | The TACoS at which profit reaches zero |
Using it for Amazon UK
Pick Amazon.co.uk and the calculator switches to pounds and the UK standard VAT rate (20%). Enter the price as shoppers see it, VAT included: the referral fee is charged on that VAT-inclusive price, while your revenue is the price net of VAT. If you are not VAT-registered in the UK, set the VAT rate to 0 and treat Amazon’s fees as including VAT. The same logic applies to Amazon.de, .fr, .it, .es and the other EU stores, each with its own VAT rate.
Where to find your numbers
- Referral fee: a percentage by category; 15% applies to most categories, but check yours in Seller Central.
- FBA fee: the fee preview for the ASIN in Seller Central (it depends on size, weight and marketplace).
- TACoS: total ad spend divided by total sales over the same period, not ACoS.
- Cost per return: the fees you don’t get back plus the share of returned units you cannot resell.
What it does not cover
- VAT on Amazon’s fees (recoverable if you are VAT-registered).
- Long-term storage surcharges, removal and disposal fees, inbound placement fees.
- Currency conversion and payment timing.
If the margin is thin, the fix is rarely one number: it is usually pricing, catalogue and advertising together. That is what a free mini-audit looks at.
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