Two pounds is the most dangerous rounding boundary in FBA: a 1.9 lb item pays $5.82 at large-standard price tier 1, while the same product at 2.1 lb pays $5.92 — and once dimensional weight pushes you past 2.25 lb, each half-pound adds $0.08. Watch the 2.00 and 3.00 lb rows before pricing.
| Billable weight | Row used | Fulfillment fee |
|---|---|---|
| up to 1.75 lb | 1.75 row | $5.57 |
| 1.76 – 2.00 lb | 2.00 row | $5.82 |
| 2.01 – 2.25 lb | 2.25 row | $5.92 |
| 2.26 – 2.50 lb | 2.50 row | $6.10 |
| 2.76 – 3.00 lb | 3.00 row | $6.67 |
| above 3.00 lb | Formula: $6.97 + $0.08 per half-pound | $6.97+ |
| Line | Value |
|---|---|
| Listed price | $29.99 (Home & Kitchen, price tier 1) |
| Actual unit weight | 30 oz = 1.875 lb |
| Packaged dimensions | 10 x 8 x 4 in |
| Dimensional weight | 10 x 8 x 4 = 320 cu in ÷ 139 = 2.30 lb |
| Billable weight | max(1.875, 2.30) = 2.30 lb → 2.50 row |
| Fulfillment fee | $6.10 base + 3.5% surcharge $0.21 = $6.31 |
| Referral fee | 15% x $29.99 = $4.50 |
The product is under 2 lb on the scale, but Amazon bills it at 2.30 lb because the box is large. On a small-parcel courier you would measure the product; with FBA you must measure the box as it leaves your warehouse.
The calculator picks the size tier, bills dimensional weight when it exceeds unit weight, and applies the right row or the 3-plus-lb formula automatically:
Large-standard fees are charged by weight row, not by continuous weight. The 2.00-lb row covers anything from just over 1.75 lb up to exactly 2.00 lb at $5.82 (price tier 1, the $10-to-$50 band). A 2.01-lb unit falls into the 2.25-lb row at $5.92. Shipping a few grams lighter, or trimming packaging, can keep you a full row down.
Past the 3.00-lb row ($6.67 at tier 1), Amazon switches to a formula: a base of $6.97 plus $0.08 for each half-pound above 3 lb. A 3.5 lb item costs $6.97 plus $0.16 = $7.13; a 4 lb item costs $6.97 plus $0.32 = $7.29. Weight rounds up to the next half-pound inside the formula.
For large-standard items FBA bills the greater of actual weight or length times width times height divided by 139. A product that weighs 30 oz (1.875 lb) but measures 10 x 8 x 4 in computes 320 divided by 139 = 2.30 lb, so it is billed at 2.30 lb — landing in the 2.50 row at $6.10 instead of the 2.25 row at $5.92. Big boxes on small products lose this game.
Yes if your price is high enough. At $29.99 in Home & Kitchen, referral is $4.50 and fulfillment around $6.31 after the 3.5% surcharge, leaving roughly $19 before product cost and ads. Below $20, the same $6-plus fulfillment fee starts squeezing margins hard — run your own landed cost through the calculator before committing inventory.