Freight Density

Freight density is the measurement of how heavy a shipment is relative to the space it occupies, calculated by dividing the total weight of the freight in pounds by its total volume in cubic feet. Density is expressed in pounds per cubic foot and is the primary factor in determining the freight class for LTL shipments, which directly affects the shipping rate. Higher density freight (more weight per cubic foot) receives a lower freight class and lower rates, while lower density freight receives a higher class and higher rates.

To calculate freight density, measure the length, width, and height of the shipment in inches, multiply to get the total cubic inches, divide by 1,728 to convert to cubic feet, then divide the total weight in pounds by the cubic feet. For example, a pallet measuring 48 x 40 x 48 inches weighing 1,200 pounds has a volume of 53.3 cubic feet and a density of 22.5 pounds per cubic foot.

Density in Cold Chain Shipping

Cold chain products exhibit a wide range of densities that affect their freight classification and shipping economics. Frozen meats and seafood are typically high density at 30 to 50 pounds per cubic foot, making them economical to ship on a per-weight basis. Fresh produce varies widely, with dense products like potatoes at 40 to 45 pounds per cubic foot and light products like lettuce at 8 to 12 pounds per cubic foot. The lighter products are more expensive to ship per pound because they consume more trailer space relative to their weight.

Understanding freight density helps cold chain shippers optimize their packaging and palletizing practices to minimize shipping costs. Increasing the density of a shipment by using smaller packaging, eliminating excess void space, or stacking cases more efficiently on the pallet can move the product into a lower freight class with correspondingly lower LTL rates. Even small improvements in density can produce significant cost savings for shippers with high LTL volumes.