How to calculate freight class
Cubic feet = L × W × H (inches) ÷ 1,728
Density (PCF) = weight (lb) ÷ cubic feet
Class = the density row it falls in below
Worked example
A standard 48 × 40 in pallet stacked 48 in high is 48 × 40 × 48 ÷ 1,728 = 53.33 ft³. At 500 lb, its density is 500 ÷ 53.33 = 9.38 PCF, which falls in the 8–10 PCF band: class 100.
NMFC density scale (from July 19, 2025)
| Density (lb per ft³) | Class |
|---|
| 50 or more | 50 |
| 35 to less than 50 | 55 |
| 30 to less than 35 | 60 |
| 22.5 to less than 30 | 65 |
| 15 to less than 22.5 | 70 |
| 12 to less than 15 | 85 |
| 10 to less than 12 | 92.5 |
| 8 to less than 10 | 100 |
| 6 to less than 8 | 125 |
| 4 to less than 6 | 175 |
| 2 to less than 4 | 250 |
| 1 to less than 2 | 300 |
| Less than 1 | 400 |
Tips to lower your freight class
- Stack boxes tightly and avoid unused space on the pallet.
- Use the smallest pallet that safely fits the load, and avoid overhang.
- Combine items into fewer, denser pallets where possible.
- Measure accurately so the carrier doesn't reclassify the shipment.
Need the volume of loose boxes first? Use the cubic feet calculator.
Last reviewed October 2026.
Frequently asked questions
What is freight class?
Freight class is a standard rating used in the U.S. and Canada to price less-than-truckload (LTL) shipments. Classes run from 50 to 500 under the National Motor Freight Classification (NMFC). Lower classes are dense, easy-to-handle freight and cost less per pound to ship.
How is freight class calculated by density?
Measure the length, width and height of the shipment in inches, including the pallet. Multiply them and divide by 1,728 to get cubic feet. Divide the weight in pounds by the cubic feet to get density in pounds per cubic foot (PCF), then look up the class on the density table.
What changed with freight class in 2025?
From July 19, 2025, the NMFC moved many items to a single 13-tier density scale, running from class 400 (under 1 PCF) to class 50 (50 PCF or more). This calculator uses that scale.
Is density the only thing that sets freight class?
No. Some items have a fixed class in the NMFC tariff, and stowability, handling and liability can also matter. Use this as an estimate and confirm the class with your carrier or the NMFC listing for your product before you ship.
Should I round up my measurements?
Yes. Carriers measure at the longest and widest points, including overhang, and usually round up to the next whole inch. Measuring the same way avoids reclassification charges.