In the business of ecommerce, few details are as crucial to get right as shipping rates. But without absolutely accurate dimension and weight information, you may be paying too much, or charging customers too little. Keep reading to see how volumetric weight can unlock more accurate rates to bring you better margins. 

Volumetric weight is a specific shipping measurement that determines the density of a package by incorporating both dimensions and weight. Also called “dimensional weight” or “dead weight,” the number comes from a simple formula: take the volume of a package, then divide it by a “dimensional divisor.” 

(Dim 1 x Dim 2 x Dim 3)➗ Volumetric divisor = Volumetric Weight

The industry standard dimensional divisor (sometimes called a volumetric divisor) is 139, but some carriers use different formulas.

  • UPS: 139 for daily rates and 166 for retail rates
  • FedEx: 139
  • USPS: 166 for Priority Mail, Priority Mail Express and Non-Lightweight Parcel Select. Currently, DIM Weight applies to Priority Mail packages 1 cubic foot or larger shipping to zones 5-9.

That number is compared against the package’s actual weight. Whichever number is higher is used as the billable weight

An 11 in x 8 in x 9 in package has an Actual Weight of 4 lbs. But would actually be rated on its Dimensional Weight of 6 lbs. We find this number by calculating: ((11 x 8 x 9)/139 = 5.7 rounded up = 6).

Why Does Volumetric Weight Matter?

Most importantly, you need to know the volumetric weight of your packages so you can charge customers the correct rates. Your carriers are already using volumetric calculations to determine transport costs. Because of this, you need to be aware of them as you build them into your shipping strategy and pass them on to buyers.

High-Density Items: If you regularly ship small but high-density items, you may not be too affected by dimensional or volumetric weight.

Example: A textbook retailer ships out a single book. The book’s dimensions are       
10 x 12 x 3, and its dead weight is 8 lbs. To find its dimensional weight, we calculate:

(10 x 12 x 3) 139 = 2.58 lbs.

While its volumetric weight is less than its actual weight, carriers will charge the greater of the two, returning a rate based on dead weight. 

Low-Density Packages: If you regularly ship low-density items, you may be surprised by how much dimensional rating is actually costing you, even though it might seem like they’d ship at a lower cost. To make up for lost space on low-density items, carriers need to charge appropriately to remain profitable. They use dimensional weight to account for the space taken up by large items, which could potentially be used to carry heavier, more cost-efficient shipments.

Example: A commercial foam retailer needs to ship three XL bags of bean bag filling to a customer. The bags go in a box that measures 24 x 24 x 24 and weighs 5 lbs.

(24 x 24 x 24) 139 = 8.2 lbs

Its DIM weight calculations show a volumetric weight of 8.2 lbs., higher than the actual weight. To subsidize the cost of carrying a large, low-density item, the carrier will rate based on the volumetric calculation. 

Making the Most of Volumetric Weight

While it may seem like an unwelcome facet of the shipping world, you can actually use volumetric shipping to your advantage by maximizing shipping efficiency.

  • Efficient Packaging – Using the smallest possible box for every order is the first and most vital step in mastering the process. If you’re not already using one, you need a tool that will automate the process and ensure every order goes in the right box.
  • Efficient Grouping – When shipping multiple products or orders at once, you may be able to leverage the system and create a single shipment that’s perfectly balanced in weight and dimensions. By pairing lower and higher density items together, you can minimize any potential losses caused by volumetric weight rating. This is especially effective if you’re making large LTL freight shipments, where many products are packed together.

ShipperHQ’s Dimensional Packing Feature

If you’re struggling with dimensional or volumetric weight, it’s time to find a solution to automate the process. Our full-featured shipping management platform has a built-in feature to help with efficiency in packing and rating.

When you integrate your store with ShipperHQ, your orders will automatically be rated and packaged in the most efficient way. This way, you’re less likely to ship orders in oversized boxes. You’ll also have full transparency into the dimensional weight of your shipments, reducing the chance you’ll be charged more than expected for a shipment.

Because most ecommerce platforms don’t have dimensional rating capability built-in, retailers need solutions like ShipperHQ to master the complex requirements of business shipping. See how our intelligent shipping logic can transform your shipping experience – and your store – starting today.

Find a full rundown on dimensional shipping, and get started with a free 15-day trial today.