How Does The "Density Based" Setting Work?

Products from Eniture Technology that provide LTL freight quotes have a product-level setting for Freight Class that includes an option for "Density Based". How does it work?

If you use a product from Eniture Technology that provides LTL freight quotes, there will be a parameter for the product-level settings labeled "Freight Class." Included in the Freight Class dropdown field is an option identified as "Density Based". Choosing this option will enable a formula that will calculate the freight class for the item based on its weight and dimensions.  The result is a calculated value that is used for the freight class of the item.

Do not confuse the calculation result with representing the shipment's freight class. Traditional NMFC tariffs allow for the price of a shipment to be based on the total weight of each freight class. This method adds the weight of the handling unit (e.g., a pallet) to the total weight of the lowest freight class without changing its freight class.

Recently some LTL providers have been pushing customers toward dimensionally rated tariffs that calculate a freight class for the shipment. This method includes the weight and dimensions of the handling unit when calculating the freight class.  The Dimensional Rating method for a shipment is sometimes referred to as the Density Rating method, which can easily be confused with identifying the freight class of an item using a density calculation.

The density calculation is an accepted industry-wide calculation. However, it is only one of four factors that determines a commodity's freight class. We strongly recommend that you identify each item's correct freight class instead of relying on the "Density Based" option in the product-level Freight Class dropdown unless the NMFC directory specifies that the commodity is density-based.

If you choose to select the "Density Based" from the dropdown as the item's Freight Class, then you are accepting, at your own risk, the results of the calculation and are knowingly ignoring the other factors that influence the freight class of a commodity. If the other factors alter the result from the density-based calculation, then the shipping quotes obtained by the app/plugin will be inaccurate.

If you choose to select "Density Based" from the dropdown as the item's Freight Class, then you are accepting, at your own risk, the results of the calculation...

How to Calculate Cubic Density for LTL Freight

There are three calculations to perform:

  1. Multiply the dimensions of the commodity (length x width x height) measured in inches. The result is total cubic inches.
  2. Divide the total cubic inches calculated in Step 1 by 1,728 (the number of cubic inches in a cubic foot) to get the cubic volume expressed in feet.
  3. Divide the weight (in pounds) by the result of Step 2 to get the pounds per cubic foot, or "density."

You can use these three steps for individual items or for handling units such as a crate, pallet, or skid.

If you have an item that will ship as multiple packages, you can also use these three steps to determine the freight density. In Step 1, calculate the cubic volume (in inches) of each package and then add them together. In Step 3, divide the total weight of all the packages by the result of Step 2.

Lookup Freight Class By Cubic Density

Use the table below to identify the freight class corresponding to your item's cubic density. Remember that cubic density is only one of four factors in the classification system for freight and that the official resource is the NMFC directory.


Freight Density
(in pounds per cubic foot)

Freight Class

Freight Density >= 50


35 <= Freight Density < 50


30 <= Freight Density < 35


22.5 <= Freight Density < 30


15 <= Freight Density < 22.5


13.5 <= Freight Density < 15


12 <= Freight Density < 13.5


10.5 <= Freight Density < 12


9 <= Freight Density < 10.5


8 <= Freight Density < 9


7 <= Freight Density < 8


6 <= Freight Density < 7


5 <= Freight Density < 6


4 <= Freight Density < 5


3 <= Freight Density < 4


2 <= Freight Density < 3


1 <= Freight Density < 2


Freight Density < 1



Related documents:

What is a freight class?

National Motor Freight Traffic Association (NMFTA)

ClassIT NMFC (Freight Class) directory registration form published by the NMFTA

Purchase a hard copy of the NMFC (Freight Class) directory from the NMFTA

What Is Dimensionally Rated LTL Freight