Freight class, density, and the reweigh

A higher LTL invoice can come from a reweigh, a class correction, added services or other rating terms. Start with the changed line item. Do not assume every difference is a class problem.

What freight class tells you

The National Motor Freight Classification, or NMFC, groups freight using density, handling, stowability and liability. Density matters, but it is not the only consideration. Use the current commodity item and its rules to determine the class. NMFTA explains how classification is maintained.

Class helps determine the charge under a carrier's pricing agreement. It does not set a universal price, and a density calculation alone does not confirm the correct commodity item.

Density, concretely

Measure the greatest packed length, width and height in inches, including the pallet and any overhang. Multiply those measurements and divide by 1,728 to get cubic feet. Divide the total packed weight in pounds by those cubic feet. This is the NMFTA method for a handling unit.

A handling unit measuring 48 × 40 × 48 inches overall occupies about 53.33 cubic feet. At 600 pounds total, its density is 11.25 pounds per cubic foot. At 1,200 pounds total, it is 22.5. Those densities may produce different classes under the applicable item; check that item before assigning either class.

Reweigh and reclassification are different

A reweigh changes the recorded weight. A dimension check changes the recorded size. A reclassification changes the class. One inspection can lead to more than one correction, but the invoice should make the basis clear.

Ask for the weight certificate or inspection record, the measured dimensions if relevant, and the item or rating rule used. Compare them with your scale records, photographs and booking details. Measurements and classification decisions can be challenged when your evidence shows an error.

Common measurement mistakes

• Using the product weight without the pallet and packaging.
• Using carton dimensions instead of the complete handling unit.
• Leaving the pallet out of the height.
• Ignoring overhang or other projections.
• Reusing measurements after the shipping configuration changes.

Check the item as well as the math

Describe the commodity specifically. Then confirm the applicable item, packaging requirements and class with your provider or NMFTA. Keep the record current as classifications change. A generic density chart is not a substitute for that check.

Density-based classification still produces a freight class. That is different from a carrier offering its own density- or space-based pricing agreement. Ask which rating method applies to your quote.

Accurate measurements give you a sound quote request and evidence if the bill changes. They do not prevent a charge for a service the shipment actually needed.

Next: Accessorials you can prevent →