Freight class, explained in plain English.

Freight class is a standardized classification used by LTL carriers in the United States. Managed through the National Motor Freight Classification (NMFC), it groups commodities into 18 classes, from class 50 to class 500. Lower classes are dense, durable, and easy to handle, and are cheaper to ship. Higher classes are light, bulky, fragile, or valuable, and cost more.

Classification is based on four characteristics: density, stowability, ease of handling, and liability. Density is usually the most important factor.

Measure the length, width, and height of the shipment in inches, including the pallet and packaging. Multiply the three measurements to get cubic inches, then divide by 1,728 to convert to cubic feet. Divide the total weight in pounds by the cubic feet to get pounds per cubic foot. That density helps determine the class.

For example, a 48 x 40 x 48 inch pallet weighing 500 pounds is 53.3 cubic feet, giving a density of about 9.4 pounds per cubic foot. Denser freight generally falls into a lower class.

The NMFC has moved many commodities toward density-based classification, reducing the number of items with fixed classes. This makes accurate measurements even more important. Carriers increasingly use dimensioners at terminals to verify size and weight, and shipments that don't match the BOL are reweighed or reclassed.

Measure the full shipment including overhang, round up to the nearest inch, and weigh the freight on a certified scale when possible. Describe the commodity clearly on the bill of lading. When in doubt, ask for help identifying the correct NMFC item before booking.