About Freight Class Calculators


To Use, Or Not To Use?

     Determining a freight class is not always a simple task. Unfortunately, there is not an easy or foolproof way to find the correct freight class.  Sure, you can find a freight class calculator on almost every freight shipping website, but each one of them comes with a small disclaimer, “freight class determined is estimated”.  The reality is, freight class calculators are too basic to determine the correct class per the commodity being shipped and can easily lead to countless re-bills due to re-classing by the LTL carrier.

Tips to understand the classing process

     The National Motor Freight Traffic Association (NMFTA) maintains the definitions for freight classes through its National Motor Freight Classification (NMFC) program.  Every type of product that can be shipped is categorized into one of 18 classes based on four characteristics:

  • Density – Is your product heavy or light?
  • Stowability - How is your shipment being packed into the vehicle?  For example, shipments that can be stacked receive a more favorable classification than shipments that require all of the space from the floor to the ceiling.
  • Handling – How difficult is it to load and unload the freight?
  • Liability – Is the freight breakable?  Does it have a high value?

Why not to use a freight class calculator

     The problem with Freight Class Calculators, is that they generalize each freight class, not being able to factor in one of the most important factors of classing a shipment, the commodity.  Being that each commodity can have up to 18 freight classes assigned ranging from Class 50 to Class 500. The higher the freight class the higher the rate for every hundred pounds. Not every commodity has all 18 classes assigned, causing the list of classes assigned to vary depending on each commodity.


Freight Density

To accurately classify your freight, all things must be considered

  • Basic description of the freight or commodity. 
  • How is it packaged:  pallets, drums, reels, crates, tubes, bundles etc.
  • Does your freight include hazardous material?  What is the description of this material?
  • Measure the length, width, and height of the object to be shipped. 
  • Weight including the packaging.

  For help classing your freight click here

     It is important to include the packaging in the weight.  The single most frequent reason for carrier price changes is stating an incorrect weight of the total packaged goods.

Once your shipment is packaged and ready to go

  • Determine the NMFC according to the definitions put out by the National Motor Freight Traffic Association.  Your carrier or broker should be able to assist in selecting the correct NMFC.  
  • Confirm if the commodity's NMFC has A density based class.   
  • Using the dimensions and weight, determine the density.  If you must use a calculator, the right one to use is a Freight Density Calculator.  
  • See what class and sub-class are associated with the density in the NMFC description.
  • Note the class and sub-class used on your BOL and or shipping documents.  

to use or not to use a freight class calculator 

     Using a freight class calculator will cause any shipper to over work themselves in re bills from unexpected freight charges.  They may not be able to figure out where they are going wrong.  The results from freight class calculators can be used to get a rough estimate of what a freight shipment might cost but be careful to make sure you have the correct class using all of the guidelines.  

For help determining the NMFC and class of your freight,  feel free to contact us at (720)242-7055  or use one of the tools below.  

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