What the fulfillment fee covers
The FBA fulfillment fee pays for picking, packing, shipping, customer service and returns handling. It is charged per unit shipped, and it is driven entirely by physical characteristics — size tier and weight. Price does not enter into it, with one exception covered below.
That is why the same $3.65 fee is trivial on a $40 product and ruinous on a $9 one, and why the fee is often the deciding factor in whether a low-priced product can work on FBA at all.
Size tier definitions
| Size tier | Max weight | Max dimensions |
|---|---|---|
| Small Standard | 16 oz (1 lb) | 15" × 12" × 0.75" |
| Large Standard | 20 lb | 18" × 14" × 8" |
| Large Bulky | 50 lb | 59" × 33" × 33"; longest side + girth ≤ 130" |
| Extra-Large (0–50 lb) | 50 lb | Exceeds Large Bulky limits |
| Extra-Large (50–70 lb) | 70 lb | Same |
| Extra-Large (70–150 lb) | 150 lb | Same |
| Extra-Large (150+ lb) | Unlimited | Same |
Small Standard rates (US, non-apparel)
| Shipping weight | Fee per unit |
|---|---|
| ≤ 2 oz | $3.06 |
| 2–4 oz | $3.15 |
| 4–6 oz | $3.24 |
| 6–8 oz | $3.33 |
| 8–10 oz | $3.43 |
| 10–12 oz | $3.53 |
| 12–14 oz | $3.60 |
| 14–16 oz | $3.65 |
Large Standard rates (US, non-apparel)
| Shipping weight | Fee per unit |
|---|---|
| ≤ 4 oz | $3.68 |
| 4–8 oz | $3.90 |
| 8–12 oz | $4.15 |
| 12–16 oz | $4.55 |
| 1–1.5 lb | $5.15 |
| 1.5–2 lb | $5.59 |
| 2–2.5 lb | $6.10 |
| 2.5–3 lb | $6.39 |
| 3–20 lb | $6.39 + $0.16 per additional ½ lb above 3 lb |
Large Bulky & Extra-Large rates
| Size tier | Base fee | Per lb above threshold |
|---|---|---|
| Large Bulky (≤50 lb) | $9.73 | + $0.42/lb above 1 lb |
| Extra-Large 0–50 lb | $26.33 | + $0.38/lb above 1 lb |
| Extra-Large 50–70 lb | $40.12 | + $0.75/lb above 51 lb |
| Extra-Large 70–150 lb | $54.81 | + $0.75/lb above 71 lb |
| Extra-Large 150+ lb | $194.95 | + $0.19/lb above 151 lb |
Surcharges and discounts on top
- Apparel surcharge: roughly $0.40 more per unit than the non-apparel rate for the same size and weight.
- Peak season surcharge (Oct 15 – Jan 14): add $0.19–$0.29 per unit to standard fulfillment fees. It coincides with peak storage rates, so Q4 gets hit twice.
- Low-Price FBA: items priced under $10 get discounted rates, averaging $0.77 less per unit. A 2 oz small standard item costs $2.29 rather than $3.06.
Why the tier boundary matters more than the rate
Within a tier, the steps are small — a few cents per weight band. Between tiers they are not. A product at 16.1 oz is Large Standard rather than Small Standard, and the fee moves from $3.65 to $4.55: $0.90 per unit for one tenth of an ounce.
The same applies to dimensions. Small Standard tops out at 0.75 inches thick; a package at 0.8 inches is charged as Large Standard regardless of weight. Before finalising packaging, check which side of each boundary you land on — reducing box thickness by a fraction is among the cheapest margin gains available.
Work out the full picture for a specific product — fulfillment, referral, storage and cost of goods together — with the FBA profit calculator, which detects the size tier automatically. For every other Amazon charge, see the complete guide to Amazon seller fees.