Dimensional Weight
Dimensional Weight (DIM weight) is a billable weight that carriers calculate from package volume. The carrier charges whichever is greater, actual weight or dimensional weight.
Why it matters for ecommerce brands
Light but bulky products are billed for space. Right-sizing cartons is often the fastest way to cut parcel spend.
Formula and example
DIM weight (lb) = length × width × height (in) ÷ divisor
UPS and FedEx commonly use 139 for daily rates. Since July 12, 2026, USPS also uses 139 for packages over 1,728 cubic inches (1 cubic foot) and rounds each dimension up to the next inch. Example: 18×14×10 = 2,520 ÷ 139 = 18.1, billed as 19 lb.
Common questions
- How do I calculate dimensional weight?
- Multiply length, width, and height in inches and divide by the carrier's DIM divisor, commonly 139. The carrier bills the greater of that number and the actual weight.
Cite this entry
"Dimensional Weight (DIM weight)." Fulfillment Lexicon, last reviewed October 16, 2026. https://fulfillment.wiki/glossary/dimensional-weight/