Freight Class & Density Calculator
*Note: This is an estimate based on density. Specific NMFC item numbers may override density-based classifications.
How to Determine Your Freight Class
In the world of LTL (Less Than Truckload) shipping, "Freight Class" is a standardized classification system defined by the National Motor Freight Traffic Association (NMFTA). It is designed to establish uniform pricing for different commodities. Understanding how to calculate your freight class correctly is essential to avoid "re-class" fees and unexpected shipping charges.
The Role of Density in Freight Class
While there are four primary factors that determine freight class—stowability, ease of handling, liability, and density—density is the most common factor for most general goods. Density is measured in pounds per cubic foot (PCF).
Our Freight Class Calculator focuses on the density method. If your product doesn't have a specific NMFC (National Motor Freight Classification) commodity code, the carrier will usually default to its density-based class.
Density-to-Class Chart
| Density (PCF) | Freight Class |
|---|---|
| Over 50 | Class 50 |
| 35 to 50 | Class 55 |
| 15 to 22.5 | Class 70 |
| 9 to 10.5 | Class 100 |
| Less than 1 | Class 500 |
Step-by-Step Calculation Example
Suppose you are shipping a pallet with the following dimensions:
- Length: 48 inches
- Width: 40 inches
- Height: 48 inches
- Weight: 600 lbs
Step 1: Calculate Total Cubic Inches. 48 x 40 x 48 = 92,160 cubic inches.
Step 2: Convert to Cubic Feet. 92,160 / 1,728 = 53.33 cubic feet.
Step 3: Calculate Density. 600 lbs / 53.33 cubic feet = 11.25 lbs/ft³.
Step 4: Determine Class. Looking at the density table, 11.25 lbs/ft³ falls into Freight Class 92.5.
Important Considerations
Always measure the extreme exterior dimensions of your shipment, including pallets or packaging. If a handle or a wheel protrudes from the side of the box, that must be included in your width or length measurement. Carriers use "dimensioners" (laser scanners) to verify these numbers, and even a 1-inch difference can trigger a costly freight re-classification.