What is Freight Classification?
Freight classification is a standardized method used to calculate shipping rates based on the characteristics of the shipment. This system, developed by the National Motor Freight Traffic Association (NMFTA), uses the National Motor Freight Classification (NMFC) to assign a class rating to Less Than Truckload (LTL) freight. The class is determined primarily by the shipment’s density and other contributing factors like handling, stowability, and liability.
Why Freight Classification is Important
Accurate freight classification ensures you get the correct rate quote and avoid unnecessary fees or delays. Carriers use the freight class, multiplied by the total weight of your shipment, to calculate the cost of transport. Misclassifying freight can result in additional charges or reclassification penalties.
How to Determine Freight Class
The primary factor in determining freight class is density—measured in pounds per cubic foot (PCF)—along with any applicable charges for high-value products. Follow the steps below to calculate it accurately:
1. Gather Shipment Information
You’ll need the dimensions of your shipment, piece count and the total weight so we can calculate the volume of space needed for transport and freight classification. Shipments are commonly palletized, so measure the length, width, and height of the pallet in inches and convert to feet.
2. Calculate the Volume
Convert all dimensions to feet, then multiply them to find the total cubic feet:
Volume (ft³) = Length × Width × Height
Example: A 48” x 40” x 72” pallet becomes 4 ft x 3.33 ft x 6 ft = 79.92 cubic feet
3. Determine the Density
Divide the total shipment weight (in pounds) by the volume (in cubic feet) to find the density:
Density (lbs/ft³) = Total Weight ÷ Volume
Example: 600 lbs ÷ 79.92 ft³ = 7.51 lbs/ft³
4. Match the Density to the Correct Freight Class
Use the NMFC or DLS chart below to find the freight class that corresponds to your shipment’s density:
| Density (lbs per cubic foot) | Freight Class |
|---|---|
| 50 or more | 50 |
| 35 – 49 | 55 |
| 30 – 34 | 60 |
| 22.5 – 29 | 65 |
| 15 – 22.4 | 70 |
| 13.5 – 14.9 | 77.5 |
| 12 – 13.4 | 85 |
| 10.5 – 11.9 | 92.5 |
| 9 – 10.4 | 100 |
| 8 – 8.9 | 125 |
| 7 – 7.9 | 150 |
| 6 – 6.9 | 175 |
| 5 – 5.9 | 200 |
| 4 – 4.9 | 250 |
| 3 – 3.9 | 300 |
| 2 – 2.9 | 400 |
| Less than 2 | 500 |
Note: A density of 7.51 lbs/ft³ falls under Class 125.
You can also use an online tool for quick calculations: DLS Density Calculator
Final Thoughts
To get an accurate freight rate quote, calculate your shipment’s density and apply the appropriate class. Don’t forget to factor in any special charges for high-value goods. When in doubt, consult a freight broker or use tools like the DLS Density Calculator to make sure your shipment is properly classified.