A safe margin after Amazon fees and ads is usually 15% or more net margin. In practical terms, if your product cannot still leave you around that level after all costs, it becomes risky once PPC, returns, and fee changes start moving.sellerapp+1
A simple rule is: keep your pre-ad profit margin high enough that your break-even ACoS still gives you room to advertise. Many sellers treat 10% net margin as the danger zone, while 15% net margin is strong and 20%+ is excellent.sellermetrics+1
So the safest answer is:
15% net margin = healthy
20%+ = very good
Below 10% = risky and hard to scale.sellerapp+1
If you want a quick shortcut, use this formula:
Selling price - Amazon fees - COGS - ads - returns = net profit.
For most new products, aim for enough margin that you can spend on ads and still stay profitable.
