Glossary → Dimensional weight
Dimensional weight.
DIM weight, billing a parcel on the space it takes up rather than what it weighs
Length times width times height, divided by a number the carrier picks, gives a weight in pounds, and you are billed on that or the scale weight, whichever is higher. The divisor is the whole argument, because a larger one bills less air: USPS moved its DIM factor to 139 effective 12 July 2026, applied to pieces over one cubic foot (Federal Register 2026-09785). Private carriers set their own and publish them on their rate pages. POD shops meet this on boxed goods rather than polybagged shirts: a mug in a void-filled carton, a canvas in a tube, a framed print with corner protectors. The quote comes off the scale and the invoice comes off the tape measure, so the gap arrives weeks later as a carrier adjustment against orders already sold at a price the shop set.