An inch you don't need is a fee you pay forever.
FBA fees step at hard size-tier boundaries. If your packaging sits just above one, a small trim drops every future unit into a cheaper tier — and cuts your storage bill with it. Enter your numbers and see how close you are.
Measure the packaged unit, not the product — Amazon bills the box.
The middle of the three dimensions.
Usually the thickness. This is the one that most often decides the tier.
Unit weight with packaging. Billed weight can be dimensional instead — we compute both.
Since 15 January 2026 the fulfillment fee depends on price as well as size — under $10, $10–$50, and over $50 are billed differently.
Used to turn per-unit savings into monthly and yearly dollars.
Where you are today
The trim that pays
Move the sliders to see your nearest cheaper tier.
If you make the change
Why the shortest side matters most. Small standard requires 0.75″ or less on the shortest side — the difference between a padded mailer and a box. If a product can ship flat, folded, or with denser packing, that one change often moves it two fee bands. And because storage is billed on cubic volume, the same trim cuts your monthly storage — which matters most in Q4, when the rate roughly triples.
Fees shown use published US FBA non-apparel rates and are estimates for comparison, not quotes — Amazon revises rates and boundaries, and categories differ. Before you re-tool packaging around a boundary, we verify the current rate card and Amazon's recorded measurement for your ASIN. That verification is part of Fee-Proof Design.
Already paying a tier you shouldn't be?
If Amazon's measurement of your product is wrong, you don't need new packaging — you need the record corrected and the overcharges refunded. That's the free audit.