Freight Class (NMFC class)

Definition

Freight class is the number an LTL carrier uses to price a shipment by how hard it is to carry. There are 18 classes, from 50 to 500. Dense, sturdy freight sits in the low classes and costs less per pound; light, bulky or fragile freight sits in the high classes and costs more.

Why it matters

Class is the input most likely to be wrong on an LTL quote, and the carrier checks it. Terminals weigh and measure freight as it crosses the dock. If the shipment turns out lighter per cubic foot than the class on the bill of lading implies, the carrier reclassifies it and bills the difference, usually weeks after the customer was quoted.

How to calculate density

Measure the shipment as it will ship, pallet included. Multiply length by width by height in inches and divide by 1,728 to get cubic feet. Divide the total weight in pounds by the cubic feet. A pallet 48 by 40 by 48 inches is 53.3 cubic feet; at 500 pounds its density is about 9.4 pounds per cubic foot. That number, not the product name, is what places most freight on the class scale.

The four things class is based on

The classification weighs four characteristics: density, handling, stowability and liability. Density does most of the work. The other three raise the class for freight that is awkward to move, cannot be stacked or loaded with other goods, or is easily damaged or stolen. Since the July 2025 classification changes, many more commodities are rated on a standard density scale instead of a fixed class per product.

Who should decide the class

The shipper knows the product and the carrier decides what it will accept, so the safest order is: the class the customer states, then a class already confirmed for that customer's commodity, then the density calculation, then a question back to the customer. When TIO's quote agent runs this step, code makes the decision in that order and a disagreement between two sources goes to a person. A language model reads the email; it does not pick the class.