Getting the USPS Discount for Irregularly Shaped Items
Posted by Doug Sherman (Import), Last modified by on 04 May 07 09:31 PM

As part of USPS's move to dimensional pricing in May of 2007, they are giving shippers a bit of a break for irregularly shaped items.  Since the dimensional pricing is based on the concept that larger items take up more room and therefore are more expensive to ship, if your item is less than rectangular, then possibly other items can be fitted around it.  Therefore, if your package is not rectangular, in the calculation of dimensional weight USPS applies a discounting factor.  After multiplying the length by the width by the height, they then apply a discount factor of .785 before dividing by 194 to determine the dimensional weight. 

USPS is the only carrier to offer this discount for irregularly shaped items when calculating dimensional weight.

This discount only applies for USPS Priority Mail for mailing to zones 5-8 (the more distant zones) when the dimensions of the item are such so that the dimensional weight exceeds 1,728 cubic inches.

Sometimes the savings can be pretty dramatic.  If after multiplying by the discount your package is no longer greater than 1,728 cubic inches, then dimensional weight is not applied at all and the actual physical weight of your item is used instead.  If it is over 1,728 after the factor is applied, you still will pay based on a lower dimensional weight.

More information on USPS's treatment of irregularly-sized items can be found here.

Our shipping engine can calculate this discount for you for appropriate items.  To include the discount for USPS, follow these steps:

  • When generating the item HTML from our HTML Wizard, be certain to include item dimensions
  • In the HTML Wizard, bring up the Additional Carrier Services popup window and select "USPS Irregular Shape."
  • You must set "Package" to "Seperately" for this item for the discount to be applied.  If you allow this item to be packaged with other items, we will assume that the package is rectangular is not qualified for the discount.

(1588 vote(s))
Not helpful

Comments (0)