If you’re still calculating Amazon profitability using the same numbers you were working with a few years ago, there’s a good chance your margins aren’t anything like you think they are.
For many brands, the full cost of selling on Amazon can now consume somewhere between 45% and 55% of revenue once advertising, FBA, storage and other operational costs are taken into account. And that’s before you’ve even considered the actual cost of the product.
The problem is, many brands are still looking at revenue and assuming that because sales are growing, profitability must be heading in the same direction.
Amazon Fees Have Changed, but Have Your Calculations?
Amazon’s fee structure doesn’t stand still. Referral fees are only one part of the equation, with FBA charges, storage, Digital Services Tax and various other costs all needing to be accounted for.
There are also fees that simply didn’t exist several years ago. Low inventory fees and other newer charges have gradually added another layer of cost, while advertising has become a much bigger part of what many brands need to spend to remain competitive.
None of these costs necessarily look disastrous on their own. It’s when you start adding everything together that the gap between perceived margin and actual contribution margin becomes much more obvious.
What Does a Real Amazon Margin Calculation Include?
To understand what you’re actually making, you need to calculate profitability at SKU level and include every cost associated with selling that product.
That starts with the landed cost and selling price, then factors in VAT, Amazon’s referral fee and the cost of either FBA or fulfilling the order yourself. Depending on the product, you may also have storage, inbound shipping, returns and damages to account for.
Advertising then needs to be considered alongside all of this.
This is where relying on a basic margin calculation can become dangerous. A product can look perfectly profitable until the complete fee stack is included, at which point you may discover you’re making considerably less than expected or, in some cases, losing money.
Why Contribution Margin Matters More Than ACoS
One of the biggest mistakes we see is brands looking at ACoS and using that alone to decide whether their advertising is profitable.
ACoS only tells you how much you’ve spent on advertising compared with the revenue those ads generated. It doesn’t know what your FBA fees are, what the product costs you or how much you’re losing through returns.
If your contribution margin is 25% and you’re running at 25% ACoS, you’ve effectively spent that entire contribution on advertising before considering anything else.
Knowing the real contribution margin gives you much better information when deciding whether to increase advertising, adjust the price, continue selling a SKU or invest more heavily in growing it.
Review Your Margins Every Month
Calculating your margins once and leaving them untouched for the rest of the year isn’t enough anymore.
We review this regularly across client accounts, updating Amazon fees, TACoS and SKU-level return rates so we’re working with current numbers. Amazon’s transaction reports are particularly useful because they allow you to see the individual fees being charged against actual sales rather than simply relying on estimates.
Once you’ve got accurate contribution margins for every SKU, rank them from strongest to weakest. The best products may have room for further investment, while weaker products might need a pricing review, cost reduction or a more fundamental decision about whether they’re worth continuing with.
Amazon revenue can keep growing while your actual profit quietly moves in the opposite direction. Revenue is vanity, profit is sanity, and knowing exactly what each SKU contributes is what allows you to tell the difference.
