Clarifying Dimensional Weight vs. Actual Weight for Shippers

August 5, 2019 by Meyer Baron
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DIM Weight Was Created by the Air Freight Industry

When air freight carriers noticed that many of the packages they carried were lighter than you would expect due to the the size of the package, they realized they were handling a lot of light packages that took up a lot of space on the aircraft.

While an aircraft can carry a lot of weight, the amount of cargo space is limited by the size of the craft. From the carrier’s perspective, if the packaged cargo is light, it makes more sense to charge by how much a package SHOULD weigh—based on the size of the package—then it does to charge based on the package’s actual weight. So, they invented DIM weight.

Having learned a lesson from their colleagues in the air freight business, LTL freight carriers have started using DIM weight in increasing numbers.

The Mystery of How DIM Weight is Calculated

The first step in determining dimensional weight is to calculate the cubic volume of the package. That’s a simple calculation of length times width times height. If the package is 15-inches long, 20-inches wide and 18-inches high, you simply multiply 15x20x18, which comes to 540 cubic inches.

But that’s as far as we can go. This is where DIM weight becomes a mystery.

A carrier will calculate the DIM weight by dividing the cubic volume by a factor it calls “the divisor.” Each carrier uses its own divisor (or set of divisors), so the DIM weight for one carrier may not be the same as the DIM weight for another carrier.

Some carriers publish the divisors they use for different types of shipments, so it’s possible for a shipper to determine the DIM weight for that carrier. But comparing the DIM weights of multiple carriers is not something shippers should even attempt to do. Honestly, as a shipper, you don’t need to know the DIM weight.

So, why did we even bring up the topic of dimensional weight? Stick with us for a minute.

Focus on Getting the Actual Weight and Dimensions Right

For actual weight, weigh your shipment after it’s been packaged and use a certified freight scale. The carrier will be sure to weigh the shipment, so don’t fudge on the weight.

Measuring the dimensions of crated freight is a simple matter of measuring the length, width and height of the crate.

When measuring dimensions of a palletized shipment, the length and width should be the same as the length and width of the pallet. Your cargo cannot hang over any of the edges of the pallet. The height is measured as a straight line from your cargo’s highest point to the bottom of the pallet where it touches the floor.

Where Dimensional Weight Comes into Play

As noted above, more and more LTL freight carriers are using dimensional weight for relatively lightweight, low density shipments that take up a lot of space.  These carriers perform a weight and dimension inspection using a dimensionalizer and certified forklift scales to determine the actual weight versus the DIM and then charge by the greater of the two weights.

Odd as it may seem, it’s possible to book a shipment based on actual weight and have the carrier bill based on DIM weight.

What’s a shipper to do to ensure a successful outcome?

Count on FreightCenter

We’ll take the guesswork out and help you determine your best pricing options. Let’s get started, get your quote today.

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