What is FBA Fee?

The FBA fulfilment fee is what Amazon charges to pick, pack and deliver one unit. It is driven by the parcel, not by the product's price, which is why two items selling for the same amount can carry very different fees.

Size tier is decided first

A unit must satisfy every limit of a tier at once: each of its sorted dimensions, its unit weight, in most parcel and oversize tiers a cap on dimensional weight, and in the largest tiers a combined limit on the longest side plus girth. The first tier it fits inside wins. One dimension over a limit promotes the whole unit to the next tier, so a box a centimetre too tall can cost more to ship than the product costs to make.

Shipping weight is the greater of two numbers

Once past the envelope tiers, the charging weight is the larger of the actual unit weight and the dimensional weight, which prices the space a parcel occupies. In the UK that is length × width × height in centimetres divided by 5,000. Envelope tiers are the exception: they classify and bill on unit weight only, and dimensional weight never applies to them.

Worked example

Suppose a unit weighs 400 g and measures 40 × 30 × 10 cm. Dimensional weight is 12,000 ÷ 5,000 = 2.4 kg, so it is charged as a 2.4 kg parcel rather than a 400 g one. Reducing the box to 35 × 25 × 8 cm brings dimensional weight to 1.4 kg without changing the product at all, and on the UK card it also drops the unit into a smaller parcel tier. Packaging is a pricing lever.

Bands step

Fees are banded, so a gram or a millimetre either side of a boundary changes the charge, and started weight intervals are charged in full. Test a design against the band edges rather than against the middle of a band.

What is on top, and what is separate

A fuel and logistics surcharge applies as a percentage of the fulfilment fee, and dangerous goods carry their own per unit addition. Storage, aged inventory surcharges, removals and disposals, returns processing and inbound placement are separate charges with their own bases: per unit stored or per unit removed, not per unit sold. Spread them per unit sold if you want them in a unit economic model, but keep them out of the per sale fee so the two are never confused.

The UK and Germany also operate a low price lane below a published price threshold, with its own bands, a weight ceiling and no dimensional weight, and several categories held to a lower threshold.

Keep the buckets clean

The fulfilment fee is charged by Amazon. A merchant or third party warehouse pick and pack cost is yours. Holding them in separate columns is what makes an FBA against FBM comparison mean anything.