# How to calculate density and figure out the class of an LTL shipment.

A shipment’s density is one of the factors that determines the freight rate. Shippers need to know how to calculate a shipment’s density so they can properly describe their goods on the bill of lading. The total weight of the shipment is divided by the total cubic feet to determine the density.

Step 1. Measure the height, width, and depth of the shipment in inches. Measure to the farthest points, including skids or other packaging.

• On shipments with multiple pieces, repeat step 1 for each piece.

Step 2. Multiply the three measurements (height x width x depth). The result is the total cubic inches of the shipment.

• If you have multiple pieces, multiply the height x width x depth for each piece. Take the results for each piece and add them together to get the total cubic inches

Step 3. Divide the total cubic inches by 1,728 (the number of cubic inches in a cubic foot). The result is the cubic feet of the shipment.

Step 4. Divide the weight (in pounds) of the shipment by the total cubic feet. The result is the pounds per cubic foot, i.e., density.

• For multiple pieces, be sure to add the weight of each piece together before dividing by the total cubic feet of the shipment.
• Round fractions to the nearest full cubic foot number.

For example, if the skid weighs 500 pounds with dimensions of 42 inches x 48 inches x 48 inches:
Multiply 42″ x 48″ x 48″ = 96,768 cubic inches
Divide 96,768 by 1,728 = 56 cubic feet
Divide 500 pounds by 56 cubic feet = 8.9 pounds per cubic feet (PCF), i.e., density

Next you will need to class the freight. Use the chart below to figure out the class of the freight

 National Classification Committee Density Guidelines Minimum Average Density (in pounds per cubic foot) Class 50 50 35 55 30 60 22.5 65 15 70 13.5 77.5 12 85 10.5 92.5 9 100 8 110 7 125 6 150 5 175 4 200 3 250 2 300 1 400 Less than 1 500