Weight brackets

Weight brackets are the bands a carrier prices by: every parcel between two weights costs the same, and crossing the boundary jumps to the next price. That step shape is why a few grams of extra packaging can cost real money, and why an average price per kilo describes nothing.

Pricing per bracket rather than per kilo changes packaging decisions. A parcel sitting just under a boundary is efficient, and one sitting just over it is paying a full band for a few grams, which is a genuinely common and genuinely fixable waste.

Missing weights are the practical problem. A variant with no weight recorded cannot be placed in a bracket, so the engine falls back to a zone-level rate and flags the gap rather than guessing, because a guessed weight silently misprices every order containing that product.

Volumetric weight is the other half of the story. Carriers charge on the greater of actual and volumetric weight, so an oversized box can cross a bracket without weighing any more, which is one more reason right-sizing packaging pays three ways at once.