Here is a great article on how the size of a package can cost you a pretty big chunk of change, so be carful when shipping large packages. In our industry, the packaging industry, a lot of our products are light but bulky and we run into this issue often. Sometimes it cannot be avoided, but it is better to know this upfront, then get hit later on with additional fees. The author of the below article also offers a great free excel spreadsheet to help calculate box sizes and if they will be hit with Dimensional fees, and what those costs will be.:
From the article:
"There are mistakes that can cost you when calculating shipping and handling fees. A big one is missing a UPS, FedEx or U.S. Postal Service DIM (dimensional) or oversize rule for large or lightweight packages.
The term “DIM” refers to package shipping density, meaning the weight of the package in pounds per cubic foot. If your package is big enough, or if the weight is small enough, the DIM rules can make your shipping costs dramatically increase.
For example, to ship a carton as small as 18” x 18” x 18”, UPS and FedEx DIM rules substitute 31 pounds as the minimum billing weight, even if the actual weight is much less. Or, for a carton as small as 27” x 27” x 27”, UPS and FedEx will add a $45 oversize surcharge on top of the DIM weight"
Jason Archambault FastPack Packaging Inc. www.fastpack.net