Compare the dimensional weight above with the actual package weight and use the heavier number to determine shipping cost *Fractions are rounded to the next whole pound.
WHAT DOES DIMENSIONAL WEIGHT MEAN?
Begining in 2015, the major carriers (FedEx, USPS, and UPS) launched new pricing called Dimensional Weight. Dimensional or DIM weight pricing is a formula that carriers use to determine the cost to ship a package based on volume. Dimensional weight pricing allows carriers to incorporate the size of the boxes they transport into their pricing.
Before 2015, the cost to ship a parcel was based on a straightforward formula. Carriers used a table that would assign a base shipping rate for every combination of weight (1-150 lbs) and zones (distance to be shipped). The heavier the package or the further it needed to travel, the more it costs to ship. This formula makes perfect sense on the surface until you think about one other factor: Companies such as FedEx, UPS, and USPS have a fixed amount of space they can use in their trucks and planes.
WHY IS DIMENSIONAL WEIGHT PRICING USED?
The reasoning behind dimensional weight pricing is to calculate FedEx, UPS, and USPS shipping costs factoring in the amount of space a parcel will take up and charge accordingly. The space each package occupies is expensive, so carriers need to factor space (dimensions) into their pricing in addition to the weight of the parcel. If your package is bulky or small, you don't need to worry about DIM prices. You'll pay for USPS shipping or shipping with other carriers based solely on the actual package weight.
However, if you ship something relatively light in a large box, you may pay more than you expected to. This is why DIM is essential to factor in when selecting packaging.
The eCommerce shipping crunch makes space in delivery trucks and vans a precious commodity. DIM weight pricing allows carriers to charge for space as well as weight.
WHAT IS A "DIM FACTOR"?
Each sender uses a number called the DIM factor to calculate a package's dimensional weight. The cost of shipping is whichever is greater between the DIM weight and the actual weight. A box with a dimensional weight of 15 pounds and an actual weight of 7 pounds would ship as a 15-pound parcel. If a package with the same dimensions had an actual weight of 10 pounds, the shipping charge would be based on the actual weight of 10 pounds.
UPS, FedEx, and USPS each set its DIM factor. This is the number by which you multiply the package dimensions to find the DIM weight. These companies update their DIM factors every year. In 2019, the US Postal Service changed its DIM weight pricing model to apply to all packages greater than 1,728 cubic inches. DIM weight pricing doesn't apply to USPS flat rate shipments.