How Does Dimensional Weight Work Anyway?

In a surprising move, the biggest shipping companies in the US have announced that they will be applying dimensional pricing to all packages starting in 2015. Previously, only large packages (over three cubic feet in size) would get hit with DIM charges. This new change could potentially lead to the biggest shipping price increase in over a decade.

Since we’re all going to start paying for dimensional weight pretty soon, it might be important to learn how to actually calculate dimensional pricing.

How to Calculate Dimensional Weight

The formula to calculate your dimensional weight is as follows:

(Length x Width x Height) / Volumetric Divisor = Dimensional Weight

The Volumetric Divisor is an arbitrary number set by the packaging company you ship with. This number may vary based on what country you’re in, where you’re shipping to, and what company you ship with. Because of the way the equation is set up, it is important to remember that the higher the Volumetric Divisor, the less chance you have of paying for dimensional charges.

By the way, it seems likely that the Volumetric Divisor is most likely going to get lower as time goes on. In 2010, major shipping companies dropped their volumetric divisors from the 190’s down to 166. Right now, international shipments usually have a volumetric divisor around 139, while US shipments are usually around 166.

Let’s do an example of how to calculate your dimensional weight. For this example, we’ll use 166 for the volumetric divisor.

So let’s say you have a five pound package being shipped in a 12″ x 12″ x 12″ box. Here’s how the dimensional pricing would work:

(12 x 12 x 12) / 166 = 10.4

So the dimensional weight is 10.4 pounds—which, obviously, is more than 5 pounds. However, we need to take into account billable weight, which means that shipping companies always round up. So in this case, you would be charged as if your package weighed 11 pounds.

If the volumetric divisor were 139 instead of 166, the dimensional weight would have been over 12 pounds.

What Can You Do to Avoid Huge Charges?

It’s pretty easy to see that this price change can have drastic effects on shipping prices. If you want to avoid paying extra for dimensional prices, I would recommend doing two key things:

  1. Educate your employees on how to calculate DIM weight and pricing. Make sure everyone understands what kind of packaging leads to pricey dimensional charges.
  2. Look for ways to cut the empty space from your packaging. Packsize studies have estimated that the average package contains 40% wasted space.


If you are looking for ways to cut some of that empty space out, On Demand Packaging® may be the right solution for you.  To learn more about what Packsize’s box-making machines can do for you, click the link below to get in contact with us: