What is Dimensional Weight (DIM)?

dimensional weight | stack of packages in front of a purple door

When you think about shipping costs, shipping weight probably comes to mind soon after: the heavier the package, the more it costs to ship. This has been the case for as long as we can remember. However, as technology has changed and we’ve gotten much better at moving packages from one place to another, physical weight is no longer as important in shipping cost calculations.

In fact, basing shipping costs solely on physical (or gross) weight has been a major financial drain on shipping companies since low-density packages can take up much more space in a delivery vehicle or shipping container than their high-density counterparts. One way shipping carriers have adjusted for that is by using what’s called dimensional weight.

What is Dimensional Weight?

Dimensional weight (or volumetric weight, DIM weight, or simply DIM) is a shipping cost calculation based on a package’s volume instead of its overall weight. Debuting in 2015 with UPS and FedEx leading the charge, many shipping carriers and logistics companies have been moving over to this new model that benefits both the shipping company and their customers.

How does Dimensional Weight Differ From Traditional Shipping Weight?

Simply put, dimensional weight is synonymous with a package’s volume augmented by what’s called a DIM Divisor – a number that carriers use to assign value to cubic inches per pound or cubic centimeters per kilogram. This is different from the traditional gross shipping weight, which is the physical weight of a package regardless of its volume.

Why the Change?

As shipping methods have improved, physical weight has become less important than how much space a package takes up in transit. For instance, a 48-foot dry van has about 3,000 cubic feet of space to work with; 50 pounds of bowling balls will take up much less space than 50 pounds of feathers. Based on traditional shipping costs, both cost the same, but more packages can fit in with a load of bowling balls vs. one with feathers.

To make their services more efficient (and to stop the tremendous financial losses and wasted resources, like fuel, associated with inefficient packaging), carriers started focusing more on volume.

While it’s true that DIM weight can cost more than gross weight, shipping customers are incentivized to choose more effective packaging types and methods to keep their volume (and shipping costs) low. This has a few benefits, including resource sustainability (better-fitting packages use less material and take up less space in shipping), increased shipping efficiency, and spurring growth in various packaging options to fit different businesses better. Using the bowling balls and feathers as an example, vacuum-sealing the feathers and condensing that package as much as possible would save a lot more money using a DIM weight model than letting them lay loose in a box to contain them all.

How is Dimensional Weight Calculated?

While different companies will charge different shipping costs based on DIM weight, the calculation remains the same:

(length x width x height) / DIM Divisor = DIM weight

The length, width, and height measurements are in either inches (if you use Imperial) or centimeters (if you use metric) to get DIM weight in pounds or kilograms, respectively.

DIM Divisors will vary depending on which carrier you use. At the time of writing, the USPS’s DIM Divisor is 166, whereas UPS and FedEx use 139. For instance, a 10” x 16” x 9” package will have a volume of 1,440 cubic inches. The DIM weight with the USPS will be roughly 8.67 pounds, whereas UPS and FedEx will value it at 10.36 pounds.

A good rule of thumb is that when you’re looking to compare DIM weight costs between shipping companies, the larger the DIM Divisor, the smaller the DIM weight – and the cheaper that cost will usually be.

From there, the shipping company will compare the gross weight with the DIM weight of your package and charge you based on whichever weight is greater. Physical weight still plays a role in logistics (how much a vehicle is weighed down will affect its fuel efficiency), so this comparison enables them to make better decisions on how to load its vehicles.

It is important to note that this formula works best with cuboid packages (your typical rectangular or square boxes); using irregularly shaped packages might increase DIM weight since calculations are based on the longest measurements for each dimension.

How to Minimize Your Shipping Costs Using Dimensional Weight

So if DIM weight might cost you more money, how do you keep your shipping costs down? Consider a few of these tips when getting your packages ready:

  • Choose the right size package for what you’re shipping: there’s no need to choose a box with a volume of 1,600 cubic inches for an item that’s only 160. While you shouldn’t skimp on protective materials to encase your products inside the shipping box, be sure to select packages that fit what you’re shipping to minimize volume (and DIM weight).
  • Explore different packaging options: you don’t have to rely on bulky boxes for everything you ship either. Use tubes for posters, maps, and other flexible/cylindrical items. Padded envelopes and sleeves are great for clothing and some kinds of jewelry. Do some research to find the packaging that’s right for you.
  • Shop around for the best shipping providers: since different providers use different DIM Divisors and pricing structures, don’t be afraid to look around for the best deals. We included some of the national carriers in the United States, but smaller regional delivery companies may have even better pricing options for you to choose from.

Save Money and Time on Shipping with UCanTrade

Considering dimensional weight is one of many ways UCanTrade helps its customers save time and money. If you’re interested in learning more about how we can help you streamline your shipping process, reach out to us today. We’ll work together to find the logistics solutions that work best for you and your business.

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UCanTrade Staff

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