If you've shipped a large box lately, you've likely run across the term "dimensional weight", or DIM weight. If your box was larger than it needed to be, this little phase probably cost you a lot of money.
So what is DIM weight? How is it calculated? And what can shippers do to reduce costs under a DIM weight pricing system?
How is Dimensional Weight Calculated?
Dimensional weight (DIM weight) is widely used by carriers such as USPS, FedEx or UPS to calculate shipping costs. Some third party logistics (3PL) companies also use a DIM weight formula. This is sometimes called a volumetric weight.
In a nutshell, the DIM weight calculation takes both the size (dimensions) and the weight of the box into consideration when determining the shipping cost. Carriers using DIM weight will charge based on the greater of two numbers: the actual weight of the package or its calculated dimensional weight. Whichever number is higher is your billable weight.
DIM weight is calculated by dividing the volume of the package in cubic inches by a DIM diviser.
- To get the volume of your box, measure the length, height and width in inches, and then multiply these numbers together. Most carriers will round up to the next whole inch for each dimension. So, a box that is 12 inches x 20 inches x 20 inches is 4,800 cubic inches (in3).
- The DIM diviser is set by the carrier. The 2019 DIM diviser for USPS is 166. So now we take our cubic volume (4,800) and divide by 166 to get 29 lbs. This is the "dimensional weight" of your box.
- If your box weighs MORE than 29 pounds, shipping costs will be based on its actual weight. But if your box weighs LESS than 29 pounds, USPS will use your dimensional weight when calculating shipping costs.
Carriers use DIM weight because large packages take up a lot of space on the truck—and space is money. The DIM weight calculation takes both the dimensions and density of the package into consideration so that carriers don't end up shipping a giant box of ping-pong balls that takes up most of the truck for next to nothing.
How to Reduce DIM Weight Shipping Costs
If you've been paying attention, you'll notice that the DIM weight calculation is really a density calculation. The DIM diviser establishes a minimum shipping cost based on assumptions about the average (or perhaps desirable) density of shipments. If your package is heavier than the DIM weight calculation—e.g., very high density—the package dimensions don't matter much, because you'll be paying based on actual weight. But shippers with very large and lightweight packages may end up with a shock when the DIM weight cost is calculated. Essentially, DIM weight penalizes large, low-density shipments.
So to beat the DIM weight formula, think dense.
- Use the smallest size box that will safely hold your items along with the packaging material needed to prevent breakage.
- Evaluate your protective packaging material options to make sure you're using the most space-efficient solution for your items. There are many different options for void fill, cushioning and protective packaging. Switching your packaging material may allow you to further decrease box size without compromising the integrity of your products.
- If you ship a large number of packages, consider renegotiating your contract with your carrier or selecting a new carrier. Different carriers use different DIM divisers and cost multipliers, which can make a big difference in your shipping costs.
Need help reducing DIM weight? Pantero can help you choose the right combination of boxes and packaging materials to minimize your shipping costs. We can even create a custom box sized specifically for your product! Contact us to learn more.