Key takeaways
- A UK FBA fees calculator must combine referral, fulfilment, storage and VAT treatment to show true net profit per unit.
- UK VAT sits on top of the sale price and goes to HMRC, while GST in Australia, Canada and India is embedded in the marketplace price.
- The same SKU can rank differently in each marketplace because fulfilment fees, referral bands and tax models vary, so rank by net profit per unit, not revenue.
- Breakeven ACOS equals net profit per unit before ad spend divided by selling price, and it moves whenever FBA fees or VAT treatment change.
- Recalculate fees every January and whenever dimensions change, Q4 storage surcharges hit, or low-inventory fees appear.
An amazon uk fba fees calculator only answers for one marketplace, and that is the problem: the same product can clear different net profit per unit in the UK, Australia, Canada and India once referral fees, fulfilment fees and VAT or GST treatment differ. Below, one product with identical price, COGS and inbound cost runs through all four fee structures in a single comparison, so you can see exactly where reorder cash appears or disappears before you list.
What does an Amazon UK FBA fees calculator actually calculate?
A UK FBA fees calculator combines four fee components into a per-unit cost: the referral fee (a percentage of sale price, typically category-based), the fulfilment fee (pick, pack and dispatch, priced by size tier and weight), monthly storage (priced per cubic foot, higher September–December), and returns processing where it applies. A calculator that skips any one of these overstates your true net profit per unit.
Referral fee vs fulfilment fee vs storage fee
The referral fee comes off your revenue before anything else. The fulfilment fee is fixed per unit by size band. Storage accrues monthly against volume held, which is why slow SKUs bleed cash even with decent ACOS.
Where to find your exact fee breakdown in Seller Central
Seller Central shows each fee per ASIN under Fulfilled by Amazon reports and the fee preview tool, though it splits them across pages. Amazon's UK FBA fee schedule lists current referral and fulfilment rates. Tools like SellerMatrix pull the same components into one per-unit view.
How do UK, Australia, Canada and India FBA fee structures differ?
The four marketplaces share a skeleton: a percentage referral fee plus a per-unit fulfilment fee. What differs is the size of the bands, how the fulfilment fee is built, and whether tax sits inside or outside the fee stack.
Referral fee bands by marketplace
Most categories land between roughly 8% and 15% referral in all four marketplaces, but the bands and minimums differ, so the same SKU can cross a band threshold in one marketplace and not another. Always check the category against the specific marketplace's fee schedule before assuming a UK margin carries over.
Fulfilment fee models: weight-handling vs flat
The UK uses a weight-handling model where the fee splits into a fulfilment component plus a weight band. Australia, Canada and India publish tiered per-unit rates by size and weight, with India's lowest bands substantially cheaper in absolute terms because they are priced in rupees. A 500g product can cost three or four times more to fulfil in the UK than in India, which flips which marketplace wins on net profit per unit.
VAT vs GST: who collects and what you can reclaim
UK VAT is your problem to account for and reclaim; marketplace-collected GST in Australia and India is largely handled at the platform level. That changes what "revenue" means before you even reach breakeven ACOS.
| Marketplace | Tax model | Fee currency |
|---|---|---|
| UK | VAT, seller accounts for it | GBP |
| Australia | GST, mostly marketplace-collected | AUD |
| Canada | GST/HST outside fees | CAD |
| India | GST, marketplace-collected | INR |
What does the same product earn in each marketplace? A worked example
Inputs held constant across all four marketplaces
Take one SKU: sale price 25.00 in local currency, COGS 6.00, a small standard-size item under 500g, 5% return rate, and PPC spend of 3.00 per unit sold. Every marketplace gets the identical inputs so the only variable is the fee structure. These numbers are illustrative, not quoted from any calculator, so rework them with your own product before drawing conclusions.
Worked calculation: UK
On a 25.00 UK sale, referral fee at 15% is 3.75, FBA fulfilment for a small parcel is roughly 3.30, and VAT at 20% takes 5.00 of the gross price. Subtract COGS, PPC and an estimated 0.50 storage and returns allowance, and net profit per unit lands near 3.15 before VAT reclaim, or closer to 5.65 if you are VAT-registered and reclaiming input VAT.
Worked calculation: Australia, Canada and India
Australia charges a 15% referral fee plus a fulfilment fee in the low single digits for a 500g item, per the Amazon Australia FBA fee schedule. Canada also runs 15% referral with fulfilment fees around 6-7 CAD for this weight band. India's referral fee sits near 15-18% depending on category, but its fulfilment fee for a 500g item is a small fraction of the UK's, and there is no VAT line on the sale itself.
The reason this comparison matters is that the same SKU can be a winner in one marketplace and a cash drain in another, and the difference rarely shows up in ACOS. In the UK, VAT alone consumes 5.00 per unit, which is more than the fulfilment fee, so a seller comparing a 25.00 UK price to a 25.00 AU price without adjusting for tax is comparing two different businesses. India looks cheapest on fulfilment, but higher referral percentages and currency conversion eat into that advantage. Canada sits in the middle: fees are moderate, but the lower price points typical of that marketplace can shrink the margin even when the fee structure is friendly. Run the same four columns for your own SKU, with your own COGS and PPC, before you commit reorder cash to any single marketplace, and tools like SellerMatrix can turn that per-unit math into a weekly true-profit figure (see how the affiliate programme works at https://sellermatrix.com/affiliates).
Reading the result: where the same SKU actually pays
Rank the four markets by net profit per unit, not by revenue. In this example the UK trails on VAT, India leads on fulfilment cost, and Australia and Canada trade places depending on your COGS currency. The ranking changes per SKU, which is why the calculation, not the conclusion, is what you should reuse.
How does VAT change the UK number compared to GST marketplaces?
UK: 20% VAT on the sale price, not on your profit
If you're VAT-registered, Amazon charges customers 20% VAT on top of your listed price, and that VAT is not yours. It goes to HMRC. Your true revenue is the sale price minus VAT, which is why a UK calculator that treats gross sales as revenue overstates profit by a sixth before you've counted a single fee.
The offset is input VAT: FBA fees, referral fees and storage fees all carry 20% VAT you can reclaim. So the fee itself is unchanged; the cash timing is what differs. Net it correctly and your true net profit per unit matches a non-VAT calculation, but your reorder cash lags until the reclaim lands. Any tool that ignores both sides of this, Sellerboard included, needs a manual adjustment in your spreadsheet. SellerMatrix treats VAT as output tax minus reclaimable input VAT per unit, so the Monday action reflects cash you actually keep.
AU, CA, IN: GST-inclusive pricing and what it does to margin math
In Australia, Canada and India, GST is embedded in the marketplace price rather than added on top. A A$29.99 listing is A$29.99 collected, and the tax portion comes out of it. Your margin math starts from a smaller revenue base than the sticker price suggests.
The practical difference: on the UK side you list ex-VAT and add it; on GST marketplaces you list GST-inclusive and subtract it. Same arithmetic, opposite direction, and mixing them up inflates AU/CA/IN revenue and deflates UK revenue. Whichever calculator you run, check that it pulls tax-exclusive figures per marketplace before you compare the four side by side.
Which FBA fees calculator should you use for each marketplace?
Amazon's native Revenue Calculator: accurate but one-SKU-at-a-time
Every marketplace has its own FBA Revenue Calculator inside Seller Central, and it pulls live fee rates for a single ASIN at a time. That makes it the most accurate source for a one-off check, especially in marketplaces where fee schedules shift often, like Canada's FBA fee schedule describes. The problem is scale: entering 40 SKUs across four marketplaces by hand is how spreadsheet Sundays happen.
Third-party profit tools compared
Sellerboard, Helium 10, tool4seller and My Real Profit all calculate per-SKU profit after FBA fees, referral fees and COGS, and most sync UK and US accounts. Fewer handle Australia or India well, so verify marketplace coverage before committing. Sellerboard is the community default for true profit tracking, and we compared it directly with SellerMatrix elsewhere on the site.
Where SellerMatrix fits, and where it falls short
SellerMatrix covers UK and US fee structures and turns Monday's numbers into one highest-impact action, but it does not currently calculate Australia or India fees, so use the native Revenue Calculator there and import the result. If your catalogue lives in four marketplaces, that gap is real and worth knowing before you subscribe.
How do you turn fee math into true net profit per unit after PPC?
A fee calculator gives you the landed cost: referral fee, FBA fee, storage, VAT. It cannot tell you what a SKU pays you after ad spend, because PPC sits outside the fee structure entirely. A SKU can clear every fee and still lose reorder cash once ACOS lands on it.
Breakeven ACOS: the number that connects fees to ad spend
Take net profit per unit before ads, divide by your selling price, and you get breakeven ACOS: the ACOS at which the SKU earns exactly zero. If a unit nets £3.20 on a £15.99 price, breakeven ACOS is 20%. Anything above that and the ad is buying revenue with reorder cash. TACOS matters too, because it shows whether organic sales are subsidising the ad-driven ones.
Why scaling ads into thin-margin SKUs creates a cashflow problem
Scale bids on a 4% margin SKU and sales rise while cash falls, because every incremental sale ships money out for inventory you cannot afford to reorder. Check breakeven ACOS per SKU before raising budgets, not after.
How often do FBA fees change, and when should you recalculate?
Amazon revises fee schedules roughly once a year, with major marketplaces announcing changes ahead of peak season. Amazon India publishes its FBA fee schedule on Seller Central, and the same pattern holds across the UK, Australia and Canada: check the schedule page each year and rerun your numbers (Amazon India Seller Central FBA fees).
Annual fee schedule updates
Recalculate every January, or when Amazon announces its annual fee changes. A 2-3% referral or fulfilment shift can flip a thin SKU negative.
Triggers for recalculating: dimension changes, low-inventory fees, storage surcharges
Run an out-of-cycle check when a SKU's dimensions change, when storage surcharges hit during Q4, or when low-inventory fees appear on a fast mover. Each of these changes your breakeven ACOS, so your PPC ceiling moves too.
What mistakes do sellers make when comparing marketplaces?
Four errors account for most bad cross-marketplace decisions. First, comparing revenue instead of net profit per unit: a SKU that looks stronger in the UK can lose to Canada once VAT, FBA fees and PPC are deducted. Second, ignoring tax treatment: UK VAT sits on top of the sale price, while GST marketplaces handle it differently, so raw revenue figures are not comparable. Third, applying US fee assumptions elsewhere, since referral and fulfilment fees differ by marketplace and can flip a marginal SKU negative. Fourth, ignoring returns rates, which vary by marketplace and eat reorder cash. The fix is one identical set of product inputs, run through each marketplace's fee structure, judged on true net profit.
FAQ
Is Amazon's own FBA revenue calculator accurate enough, or do I need a paid tool?
For a single ASIN, Amazon's native Revenue Calculator is the most accurate option because it pulls live fee rates. It fails on scale: checking 40 SKUs across four marketplaces by hand is slow. A paid tool earns its keep when you want per-SKU profit synced weekly, but verify it covers Australia and India before subscribing.
How do I calculate breakeven ACOS once FBA fees are included?
Take your net profit per unit after referral fees, FBA fees, storage, VAT and COGS, but before ad spend. Divide that figure by your selling price. A unit netting £3.20 on a £15.99 price gives a breakeven ACOS of 20%. Above that, ads are buying revenue with reorder cash rather than profit.
Do I charge VAT on top of my FBA fees in the UK?
No. You charge VAT on the sale price, which goes to HMRC, not on the fees Amazon charges you. The offset is input VAT: FBA fees, referral fees and storage all carry 20% VAT you can reclaim. Net both sides correctly and your true profit matches a non-VAT calculation, though reclaim cash lags.
Which marketplace is most profitable for the same product, UK or Australia?
It depends on your SKU, not the marketplace. In a worked example with identical inputs, the UK trailed because 20% VAT consumed 5.00 per unit, more than the fulfilment fee, while Australia's GST is embedded in the price. Run the same inputs through both fee structures and rank by net profit per unit.
How much does Sellerboard cost compared to doing it in a spreadsheet?
A spreadsheet is free but manual: you update fees, VAT and PPC per SKU yourself, which breaks at scale. Sellerboard automates per-SKU profit tracking after FBA fees, referral fees and COGS, and is the community default for true profit tracking. Check current pricing on their site, since plans change.