That’s any box with a cubic area equivalent to or larger than 1,728 inches. The changes that the US Postal Service instituted in June 2019 apply only to packages over 1 cubic foot in total area. Read on for examples of how DIM weight pricing can affect your USPS shipping costs.

However, if you ship something relatively light in a large box, you may pay more than you expected. You’ll pay for USPS shipping (or shipping with other carriers) based solely on the actual package weight.

If your package is heavy or small, you don’t need to worry about dimensional weight. After all, the number of packages that can fit on one truck or in one container depends as much on the size of the box as its weight. DIM weight pricing allows carriers to incorporate size as well as weight into their price structure. What is dimensional weight?ĭimensional or DIM weight is a formula that carriers use to determine the cost to ship an oversized package. That knowledge will help you keep your USPS shipping costs as low as possible. Understanding dimensional weight is critical for eCommerce fulfillment of large products or shipments. And, in 2022, USPS introduced a new oversized shipping fee for “dimensional noncompliance.” However, USPS has a higher DIM factor than most carriers, so its surcharge for large items is smaller (we break down the math below). USPS joined FedEx, UPS, and DHL in applying a size-based formula for oversized boxes. In the summer of 2019, the US Postal Service changed the way it calculates shipping charges.

Usps large flat rate box cost 2019