What is USPS Soft Pack in Shippo?

Soft Pack refers to parcels shipped inside of bags/sacks with the Priority Mail service level. These shipments qualify for a certain type of cubic pricing - Apparel is often shipped with Soft Pack.

Soft Pack uses a different formula to determine the Cubic Pricing of the shipment. That formula is Length (rounded down to nearest quarter inch) + Width (rounded down to nearest quarter inch). The typical formula for Cubic Pricing is LxWxH/1728. (1728 is 12 ┬│ e.g. one cubic foot). 

The benefit of Soft Pack to customers is that the parcel, which may not qualify for Cubic Pricing otherwise, does qualify for Cubic Pricing, and the price may be lower than the alternative Priority Mail rate.

Cubic Price Tier Sum of Length + Width
.1 0" up to 21"
.2 more than 21" up to 27"
.3 more than 27" up to 31"
.4 more than 31" up to 34"
.5 more than 34" up to 36"

To qualify for a Soft Pack rate:

  • From the Orders page, navigate to the order you would like to ship in a soft pack. 
  • On the order, open the Package Info section. 
  • Open the Package dropdown menu and select Carrier Provided Parcel
  • Then, scroll down and choose Soft Pack from the Package drop-down menu.
  • Lastly, enter in your package dimensions, click Save, and view your rate!

Unlike most Parcel Templates that have pre-defined dimensions, you must input the length and width for the mailer




Soft Pack pricing does not utilize weight values, however we still require these to be entered in Shippo. Should the parcel not qualify for Soft Pack pricing, entering these dimensions will allow Shippo to return non-SoftPack Priority Mail rates.



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