Effective June 23, 2019, the USPS is making changes to its pricing structure for Priority Mail, Priority Mail Express, and Parcel Select related to dimensional weight pricing.
What is dimensional weight pricing?
Dimensional weight, also known as volumetric weight or DIM weight, is an estimated weight that is calculated from the length, width and height of a package. It is used to ensure that fair postage costs are paid for large, lightweight packages that take up more room during transport.
Dimensional weight is calculated by multiplying the length, width, and height of a package, then dividing the result by a specific number (known as the dimensional factor, set by the carrier). The USPS has traditionally used a factor of 194 when calculating dimensional weight.
If the resulting calculation is less than the package’s actual weight, the actual weight is used to determine postage costs. If the dimensional weight is greater, that is used to determine postage costs. The dimensional calculation only applies to parcels over 1 cubic foot in volume.
What changed on June 23, 2019?
Previously, dimensional weight pricing only applied to packages shipped via Priority Mail to zones 5-9, and used a factor of 194.
After June 23, 2019, dimensional weight pricing for Priority Mail will apply to zones 1-9, and will begin to calculate dimensional weight using a factor of 166.
Further, packages shipped through Priority Mail Express and Parcel Select to zones 1-9 will now be subject to dimensional weight pricing as well, using the updated factor of 166.
You can read more about these changes on USPS.com.