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Four rules of determining freight class when shipping machinery

(Photo credit: Jim Allen/FreightWaves)

Freight class is a measurement you can use to determine how much it costs to ship items, such as machinery, using less-than-truckload (LTL) freight shipping. LTL freight is a shipping method in which you’re charged based on the amount of space your cargo takes. Because of this, density is the main factor in how much you’ll pay. However, it’s not the only thing to consider when shipping freight.

There are 18 freight classes designed to streamline the pricing process for those wanting to ship items like heavy machinery. Generally, the less dense the item, the more it will cost you – but costs vary depending on other factors, including stowability and liability.

Failure to accurately determine your National Motor Freight Classification (NMFC) freight class can result in a freight reclassification, which costs time and money.

(Photo credit: Jim Allen/FreightWaves)

Here are four rules you can follow to determine freight class when shipping machinery.


1. Know what you’re shipping
To ship your item, you’ll need both freight code and the freight class. The National Motor Freight Traffic Association publishes a complete list of all freight codes and classifications that you can use to determine the code of the item you want to ship.

If in doubt, however, contact the manufacturer of your item. It will likely have the freight code on record, sparing you the possibility of incorrectly coding your freight. Individual items have a fixed freight class – no matter the size, weight or density of the item. In cases like these, not knowing your item’s freight code can easily result in a costly reclassification.

2. Calculate item density
Freight class is inversely related to the density of the freight shipped. The higher a freight class, the lower the density.

To calculate the density of your machine, you’ll need the dimensions – length, width and height – of the pallet your device will be transported on. You’ll also need your machine’s weight in pounds. Exact measurements are necessary. Like with the freight code, your manufacturer should be able to provide specific measurements if you’re unable to find them. Your machine’s density is the weight divided by the length, width and height.


To find what density this weight class corresponds to, you can use one of several online freight class calculators. You can also contact the freight company or broker you plan to work with.

3. Work in other factors
Once you’ve calculated density, you’ll need to work in other factors that can change the freight class of your package or affect how much you can expect to pay in shipping.

Stowability, liability and ease of handling can all affect your freight class. If an item is particularly tricky to stow or transport, or if it is vulnerable to theft or damage, you may need to pay more. When shipping machinery, there are other considerations to keep in mind – including whether or not the machine is under- or oversize, which may increase shipping costs.

Typically, density will be enough to find the freight class of your machinery. If you’re concerned other factors may make your item more expensive to ship, reach out to the freight company or broker you’re working with to avoid the possibility of a freight reclassification.

4. Consider specialty packaging
When measuring the dimensions of your item, wait until it’s completely wrapped and packaged. If you measure the item before you pack it, you’ll likely come up with the wrong weight and dimensions.

Choose the right type of packaging to prevent damage to machinery. In some cases, specialty packaging – such as shrink wrap, vacuum and shock mount packaging – may also change the freight code of your item.

(Photo credit: Shutterstock)

How to determine freight class when shipping machinery
In many cases, a freight class calculator to determine your item’s density is enough to accurately determine the freight class of your item.

However, in some cases, factors like stowability, liability, ease of handling and packaging type can change the cost of shipping. In some cases, items may have a fixed freight class, and you won’t be able to calculate the cost without first looking it up.


Contacting a freight company or broker with experience in LTL shipping is one of the best ways to ensure you class your item correctly and save money.

Kayla Matthews

Kayla Matthews is a technology journalist and writer interested in manufacturing and the supply chain. Her work has been published on Thomas Insights, Industrial Machinery Digest, American Machinist and Manufacturing.net.