I didn't see anything on here about "Phase 2" of this year's USPS price increases that take effect 23 June - "having to do with DIM Weight. That stands for dimensional weight, a pricing method shipping carriers came up with to charge more for packages that are lightweight, but take up a lot of room."
I've sent an e-mail to support to see if they are going to make any changes to the shipping calculator or if we will have to figure it out for ourselves and mark anything that is more than 1 cubic foot as "Oversize Package".
What’s Changing on June 23rd
Currently the USPS DIM divisor is 194, and it only applies to Priority Mail parcels larger than a cubic foot for packages going to zones 5-9.
Beginning June 23, the USPS is changing the DIM divisor from 194 to 166 (the lower the number, the higher the rate); it’s expanding DIM Weight to
all zones; and it’s expanding DIM Weight pricing beyond Priority Mail to include Priority Mail Express and Parcel Select Ground.
What is not changing is the box size – USPS DIM Weight still applies only to boxes larger than a cubic foot (1728 cubic inches).
https://www.ecommercebytes.com/2019/...tal-rate-hike/