Most Amazon sellers overestimate their profit because they forget fees. The difference between your gross margin and actual net profit on Amazon FBA can be 15-20 percentage points once you account for every cost — referral fees, fulfillment fees, storage, PPC advertising, and returns. Here's the complete Amazon FBA profit formula with a real-world calculation example and the best profit tracking tools for 2026.
Net Profit = Sale Price − COGS − Referral Fee − FBA Fee − Storage Fee − PPC Cost − Returns Cost − Misc Fees
| Line item | Amount | Notes |
|---|---|---|
| Sale price | $29.99 | |
| COGS (landed cost) | −$5.50 | Product + shipping from supplier |
| Referral fee (15%) | −$4.50 | Standard for most categories |
| FBA fulfillment (1 lb) | −$3.50 | Pick, pack, ship |
| Monthly storage | −$0.15 | $0.87/cu ft prorated per unit |
| PPC advertising (15%) | −$4.50 | Typical ad spend ratio |
| Returns (~5% rate) | −$0.53 | Return processing + unsellable units |
| Inbound shipping | −$0.40 | Ship to Amazon fulfillment center |
| Net profit | $10.91 | 36.4% margin |
That's a healthy product. But if your COGS were $9 instead of $5.50, net profit drops to $7.41 (24.7%). If PPC is 25% instead of 15%, profit drops to $7.91 (26.4%). Small changes in any variable swing profit dramatically.
Sellerboard shows exact profit per unit, per day, per product — including fees Amazon hides.
For a deeper understanding of every fee in the formula above, read our complete FBA fees breakdown. If your margins are tight, our guide on how to reduce Amazon FBA fees covers 9 strategies that can save $0.50-$2.00 per unit. You might also benefit from AI tools for optimizing your listing copy — see the best AI writing tools for ecommerce.
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