2019 Dimensional (DIM) Weight Pricing Changes
Your packaging matters. Lighter weight, lower density packages are comparatively less profitable for carriers because they take up so much space relative to the price charged per package (based on weight alone). Looking for ways to adjust this model, carriers started using dimensional (DIM) weight rates. DIM weight rates allow carriers like the USPS to establish a minimum charge for the cubic space a package occupies. DIM weight is calculated by multiplying the length by width by height of each package (in inches) divided by carrier divisor for shipments. The current divisor for USPS is 194, but that will change to 166 on June 23, 2019.
Changes to Priority Mail®:
Starting June 23, 2019: Dimensional Weighting, which currently applies for Zones 5-9 will apply for all Zones 1-9, and the DIM factor (divisor) will change from 194 to 166.
Changes for Priority Mail Express®:
Starting June 23, 2019: Dimensional Weighting will be new for Priority Mail Express and will apply for all Zones 1-9. The DIM factor (divisor) will be 166.
Changes for Parcel Select:
Starting June 23, 2019: Dimensional Weighting will apply for all Zones 1-9. The DIM factor (divisor) will be decreased from 194 to 166.