Choosing the Correct Freight Class

A word of warning, determining Freight Class can at times seem overwhelming. The industry is in the middle of a shift in the way that class is determined. Some Carriers are sticking to the old ways and rating class by NMFC Codes, while other Carriers are looking to maximize the space available in the their trucks by switching to Volumetric Pricing. This article will give an overview of both ways with a focus on the future.

NMFC Codes

Until very recently, the use of NMFC Codes was the standard for all Carriers when it came to determining freight class. NMFC stands for National Motor Freight Classification.The codes are broken out into classes that encompass the world of shippable items. Items are broken out into categories and then broken down even further into more detailed subcategories.

For example, if you wanted to ship some paintings you would go to the 'Art Objects' codes which start with 052 and then find the code that paintings fall under, which is 05256. These codes are then broken out into the 18 Freight Classes, which can be seen below.

This system is simple in concept, but the variety of shippable items leads to a large list of codes that needs to be sorted through in order to pick the correct code. Some Carriers are attempting to sidestep this system all while maximizing the space in their trailers. This has led to them switching to a Volumetric Pricing structure.

Volumetric Pricing

The basic idea behind the Volumetric Pricing structure is maximization of space. A trailer is finite space and Carriers can only load so much into that space. In order to do that and make money on a load, Carriers need to balance out each load with shipments that make them money but allow them to ship the most per load. There are four major components that go into determining the freight class when using the Volumetric Pricing structure, these are density, stowability, handling, and liability.

1. Density

Density is the biggest factor when determining freight class. Figuring out a shipment's density is simple. First you need to calculate the Length, Width, and Height of the shipment and multiply them together. Once you get that number (assuming you did these calculations in inches) you divide that number by 1728. That is the Volume of the shipment. In order to find the density, you need to divide the Weight (mass) by the Volume you just figured out. That number is the Density of the shipment. This number is measured in pounds per cubic foot. This allows you to more easily pick a freight class. The Classes range from Class 50 which is defined as an item with a weight range of more than fifty pounds per cubic foot and is usually the cheapest to ship, to Class 500 which are items with a density less than 1 pound per cubic foot.

For reference, here's a chart of all 18 Classes with a brief description.

2. Stowability

Stowability is how easily something fits onto a truck. For most freight, this isn’t a major issue. The majority of  freight stows easily and can ship well with other items. However, there are those cases when an item is excessively heavy, long, or misshapen to a point that shipping it with other items is difficult and even impossible. Other factors that go into stowability are if there isn’t a sufficient load bearing surface area to stack on top of.

In recent years Carriers have gotten a lot smarter about how they load their trucks. This sometimes translates into shippers getting charged for unusable space their shipments cause due to their abnormal sizes. Not all Carriers do this, but it is becoming increasingly prevalent, especially with the advent of volumetric pricing across the industry. A little forethought when putting your shipment together can alleviate a lot of headaches and charges down the road.  

3. Handling

Your average freight shipment is loaded and unloaded from the truck with the use of some type of mechanical equipment like a fork lift. If the item being shipped is heavy, misshapen, too fragile to be moved in a normal fashion or is hazardous in any way, it may lead to a class change and additional charges.

4. Liability

Liability refers to the probability of a shipment being stolen, or damaged. If you are shipping high value items or items that are easily broken, the carrier is going to charge more to cover themselves in the likelihood of something going wrong.


The switch to Volumetric Pricing is a slow one, which means you need to be aware of both ways of determining freight class. For the time being, only a few Carriers have made the switch. These Carriers tend to be the budget Carriers who are trying to get the most out of every truck.

The bigger Carriers are still using the old system due to its easier, less hands on approach to picking a freight class. Freight class is a necessary evil in the shipping world, it's not always the easiest part, but having a working knowledge of its ins and outs will make shipping a much more delightful experience.