In the world of LTL freight shipping, understanding the principles of density can sometimes be half the battle. It is a principle that I was taught the very first day when I was first hired into the LTL industry and serves me well to this day. Once your first question about a shipment becomes, “What is our density?”, you’ll be a shipping pro in no time.
The formula for calculating density can be broken down into a few, easy steps.
- Let’s start by breaking this down one piece at a time. L=Length, W=Width, and H=Height. Take a good working tape measure and measure the longest point of the piece of freight (not the pallet but the freight itself). Also, apply this same principle to the width (widest point of the shipment) and the height (highest point of the freight from the floor to the top) of the freight.
- After measuring, let’s say this piece of freight comes out to 44 inches in length, 48 inches in width and 57 inches in height.
- Now that we have our dimensions – 44L x 48W x 57H – we do the multiplication. 44x48x57=120,384 cubic inches.
- Take 120,384 and divide that by 1728. (1728 is the number you will always use to divide your cubic inches by, no matter what!). 120,384/1728=69.66. 69.66 is now your Cubic Footage.
- We know that our cubic footage is 69.66 but what is our weight? If you are going to be shipping freight, the last thing you want to do is estimate, eyeball, guesstimate or have a wild hunch about what the weight is. You want to invest in a proper, well calibrated, high durability freight scale. You also do not want to weigh just the items that you are shipping. You want to weigh the entire shipment (pallet, plastic wrap, items and all as they will be shipped).
- After weighing your freight on your calibrated scale, the scale shows a weight of 957lbs.
- Now that we have our weight of 957lbs we divide that weight by our cubic footage which was 69.66. 957/69.66=13.73 pounds per cubic foot.
Now that we have our density, or pounds per cubic foot, what is our Freight Class?
Freight class is almost always determined by where the density or poundage per cubic foot falls on the Full Range Density Chart (see below)
|Class 400||Less than 1|
|Class 300||More than 1, but less than 2|
|Class 250||More than 2, but less than 4|
|Class 175||More than 4, but less than 6|
|Class 125||More than 6, but less than 8|
|Class 100||More than 8, but less than 10|
|Class 92.5||More than 12, but less than 15|
|Class 85||More than 12, but less than 15
|Class 70||More than 15, but less than 22.5|
|Class 65||More than 22.5, but less than 30|
|Class 60||More than 30|
We know that our density for this shipment is 13.73, therefore based on the scale above, our freight class would be Class 85 as 13.73 is more than 12 but less than 15 in terms of pounds per cubic foot. Now, whenever you are quoting this shipment it should be quoted at Class 85 so that the shipment is appropriately priced. However, factors apart from density can affect the price of a shipment.