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What Is Freight Class?

Freight class is a standardized way of classifying commodities for Less Than Truckload (LTL) shipping.

It is commonly associated with the National Motor Freight Classification (NMFC) system and helps carriers and shippers evaluate how freight should be handled, priced, and transported.

Why does freight class matter?

Freight class helps describe how easy or difficult a shipment is to transport.

It can affect:

  • the shipping rate
  • how the freight is handled
  • how it is loaded with other freight
  • the carrier’s risk when transporting it

The NMFC system provides standardized commodity classifications that help create consistency across LTL shipping.

For more information about NMFC standards, visit the National Motor Freight Traffic Association (NMFTA).

How is freight class determined?

Freight class is generally influenced by four main factors:

  1. Density
    The amount of space the freight occupies compared with its weight.
  2. Ease of handling
    Freight that is unusually shaped, fragile, heavy, difficult to move, or requires special handling may be classified differently.
  3. Liability
    Freight that is more susceptible to theft, damage, spoilage, or other risk can affect classification.
  4. Stowability
    Freight that cannot easily be loaded with other shipments, or that is subject to special restrictions, may receive a different classification.

How do I calculate freight density?

To calculate freight density:

  1. Measure the length, width, and height of the freight in inches, including the packaging.
  2. Multiply the three dimensions to calculate the total cubic inches.
  3. Divide the cubic inches by 1,728 to convert the measurement to cubic feet.
  4. Divide the shipment weight in pounds by the total cubic feet.

The formula is:

Length × Width × Height = cubic inches

Cubic inches ÷ 1,728 = cubic feet

Weight in pounds ÷ cubic feet = density

Does density always determine freight class?

Not necessarily.

Density is an important factor, but freight class may also depend on the commodity itself and how it is listed under the NMFC system.

For example, two shipments with similar density may still have different freight classes because of differences in handling requirements, liability, stowability, or commodity classification.

Can I use an online freight class calculator?

Yes. An online calculator can help estimate freight density and possible freight class.

You can use this Freight Class Calculator as a reference.

Keep in mind that calculator results are estimates. The final freight class should match the applicable NMFC classification and carrier requirements.

Do all carriers use NMFC?

Not every transportation provider applies NMFC rules in exactly the same way.

Carriers that reference NMFC classifications in their tariffs, contracts, or rate structures use those standards as part of their freight-rating process.

For specific questions about NMFC participation or classification standards, visit NMFTA.

If you need help creating an LTL shipment in ShipTime, contact our Heroic Support™ team.

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