40
13. Appendix 2: Dimensional Weight & DIM FACTOR
13.1. The Importance of Volume and Weight of Cargo for Transportation
All cargo space involved in transporting goods has physical limits based on the volume of the cargo
and the weight. Once a cargo has reached a limit in either volume or weight – the container (trailer,
train, plane or shipping container) is transported. Weight has traditionally been the measurement
which the transportation costs of individual packaged freight has been calculated.
The difference in weight and volume costs can be appreciated if one considered the expense of
transporting a large volume with little weight (e.g. large boxes of Styrofoam drinking cups).
Transportation companies have recognized these variables and most have allocated a volume per
weight standard in their billing to capture cargo of light density.
13.2. Dimensional (Volume) Weight
The dimensional weight (also known as volume weight) is the minimum weight that a package a
given size may have that is handled by a carrier. A carrier may state that any package of one cubic
foot (12”x12”x12”) will have a minimum weight allowance of 10 pounds. If the cubic foot package
actually weighs 8 pounds – it will be invoiced for 10 pounds. This is a
minimum
weight allowance –
if the cubic foot package weighs 12 pounds – the charges will be based on 12 pounds.
"
There are no international or domestic standards concerning values of dimensional
weight. A significant number of courier companies use the dimensional weight standard set
by the International Air Transport Association (IATA) but many define their own dimensional
weights.
The value of dimensional weights will probably change as the nature of shipments change over time.
Organizations such as the International Air Transport Association (IATA) have produced studies that
suggest the density of packaging is changing as the commodities become more high tech. As a
result the IATA itself has already passed a resolution (Resolution 501) to change the IATA
dimensional weight.
