The USPS Dimensional (DIM) Weight Pricing Changes, Effective June 23, 2019

On June 23, 2019, the USPS implemented changes to its Dimensional (DIM) weight pricing policies. This has a big impact on e-commerce merchants shipping packages that are especially large and lightweight.

Here’s the good news: if your packages are less than or equal to 1 cubic foot in volume [meaning the volume (or L x W x H) of your package is less than or equal to 1728 cubic inches], then this change will not impact you.

If you do have larger packages, read on to learn more about the changes and what they mean for your shipping mix.

How did the USPS Change its Dimensional (DIM) Weight Pricing Policies?

• Dimensional (DIM) weight pricing now applies to all Priority Mail, Priority Mail Express, and Parcel Select packages measuring larger than 1 cubic foot. (Previously, DIM weight was limited to only Priority Mail packages traveling via Zones 5-8 and larger than 1 cubic foot).
• The Dimensional (DIM) weight factor decreased to 166 (down from 194). Ultimately, this means that packages that qualify for Dimensional (DIM) weight, saw a price increase with the new changes. See below for more details.
• Balloon pricing was eliminated for Priority Mail, Priority Mail Express, and Parcel Select.
• Here’s a chart to compare the new policies versus the old:  

What is Dimensional (DIM) Weight Pricing?

Dimensional (DIM) weight pricing is the carriers’ way of encouraging shippers to optimize their box sizes to prevent wasted space inside the boxes which, in turn, wastes space in their trucks. If the package is larger than 1 cubic foot in volume, then the carrier will determine the package’s dimensional weight (based on the size of the package) and compare that to the physical weight. The weight that is higher will be used to determine the shipping rate.

Ultimately, this affects e-commerce businesses owners that ship large, lightweight packages (think: lightweight poster frames). Because the package’s dimensional weight will likely be high and its physical weight will be low.

Dimensional (DIM) Weight Calculation Examples

Let’s take a look at how to calculate Dimensional (DIM) weight, using the new DIM weight factor and the following calculation:

Dimensional weight = Package Volume / DIM weight factor

USPS Dimensional weight = ( L x W x H ) / 166

Example 1: Poster Frame

• Package dimensions: 24 inches x 36 inches x 3 inches
• Package weight: 3 pounds
• Package Volume: 24 x 36 x 3 = 2,592 cubic inches
• Does this qualify for DIM weight? Yes, because the volume is greater than 1,728 cubic inches.
• Dimensional weight: 2,592 / 166 = 15.61 (rounds up to 16 pounds)
• 3 pounds < 16 pounds

In this case, you pay for a 16-pound package, instead of the physical weight of 3 pounds.  

Example 2: Large Bag of Fertilizer

• Package dimensions: 16 inches x 5 inches x 24 inches
• Package weight: 45 pounds
• Package volume: 16 x 5 x 24 = 1,920 cubic inches
• Does this qualify for DIM weight? Yes, because the volume is greater than 1,728 cubic inches.
• Dimensional weight: 1,920 / 166 = 11.5 pounds (rounds up to 12 pounds)
• 45 pounds > 12 pounds

In this case, you pay for the physical weight, since 45 pounds is greater than 12 pounds.

Example 3: The Lampshade

• Package dimensions: 13 inches x 13 inches x 8 inches
• Package weight: 2 pounds
• Package volume: 13 x 13 x 8 = 1,329 cubic inches
• Does this qualify for DIM weight? No, because the volume is less than 1,728 cubic inches.

In this case, the package does not qualify for DIM weight, so you will purchase postage based on package weight, like usual.

How Will These Changes Impact My Carrier Mix? A FedEx vs. UPS vs. USPS Rate Comparison

Let’s use these same examples to see how the new USPS rates will compare with FedEx and UPS.

First, it’s important to know that UPS and FedEx also have Dimensional (DIM) weight policies. All UPS Air and Ground packages qualify for Dimensional (DIM) weight pricing, while all FedEx Express and Ground packages qualify. Unlike FedEx and UPS (where all packages qualify), USPS packages do not start qualifying for Dimensional (DIM) weight pricing until their volume is greater than 1,728 cubic inches.

Also, both UPS and FedEx use a Dimensional (DIM) weight factor of 139 (versus the Postal Service’s 166).

Example 1: Poster Frame

• Package dimensions: 24 inches x 36 inches x 3 inches
• USPS Dimensional weight: 16 pounds

Example 2: Large Bag of Fertilizer

• Package dimensions: 16 inches x 5 inches x 24 inches
• Package weight: 45 pounds

Example 3: The Lampshade

• Package dimensions: 13 inches x 13 inches x 8 inches
• Package weight: 2 pounds

How Will This Impact My Shipping Carrier Mix?

As you can see above, if your package volume is less than or equal to 1 cubic foot, the U.S. Postal Service is typically a very competitive option—especially for lightweight packages. If your package is large enough to qualify for USPS Dimensional (DIM) weight pricing, the three major carriers have similar shipping rates. Traditionally, FedEx and UPS are great options for heavier packages, but the examples above show that the USPS can be competitive here, as well.

And, if you use a shipping software like Shippo, the rates are automatically calculated, so you don’t have to worry whether you’re choosing the correct rate, because we’ll choose the correct rate for you.

If you have any questions, don’t hesitate to get in touch at sales@goshippo.com.