Amazon FBA vs FBM Calculator
Should Amazon fulfill the order or should you? Enter your price, product cost and fulfillment figures to see net profit per unit under both methods, using 2026 US referral and FBA rates, plus the exact shipping cost at which FBM becomes cheaper.
FBA also gives automatic Prime eligibility; FBM gets it only through Seller Fulfilled Prime. That traffic value is not included in the math.
2026 US fees used in this comparison
| Fee | 2026 rate |
|---|---|
| Referral fee (most categories) | 15%, $0.30 minimum |
| FBA small standard fulfillment | $2.43 – $2.95 (non-peak) |
| FBA large standard fulfillment | $2.91 – $5.47+ (non-peak) |
| Peak fulfillment (Oct 15 – Jan 14) | about $0.20 – $0.55 higher |
| Monthly storage (standard, Jan–Sep) | $0.87 / cu ft base |
| Monthly storage (Oct–Dec) | $2.40 / cu ft base |
Figures from Amazon Seller Central, “Standard selling fees”, “2026 US FBA fulfillment fee changes” and “Monthly inventory storage fees”. Actual fees depend on size tier, weight, category and season.
Frequently asked questions
What is the difference between FBA and FBM?
With FBA (Fulfillment by Amazon) you send inventory to Amazon, which stores, packs and ships orders and handles most returns. With FBM (Fulfillment by Merchant) you list on Amazon but store inventory and ship orders yourself.
Do I still pay the referral fee under FBM?
Yes. The referral fee is charged on every Amazon sale regardless of who fulfills it. FBM removes the FBA fulfillment and storage fees but replaces them with your own shipping and packaging costs.
When is FBA usually cheaper?
FBA is typically better for small, light, fast-selling items where its fulfillment fee is competitive with your own shipping, and where Prime eligibility drives extra sales. Storage fees make slow-moving inventory expensive.
When is FBM usually cheaper?
FBM is often better for heavy, bulky or slow-moving products, or when you already have cheap shipping, because you avoid FBA storage and the new FBA-only surcharges. You must still meet delivery expectations to keep account health.