Freight class is the rating LTL carriers use to price a shipment. There are 18 classes from 50 to 500, published in the National Motor Freight Classification (NMFC). Lower classes are dense, sturdy freight and cost less per pound; higher classes are light, bulky or fragile freight and cost more. For most commodities, density is what decides the class.
How to work out density
- Measure the shipment's length, width and height in inches, including the pallet and any overhang.
- Multiply them and divide by 1,728 to get cubic feet.
- Divide the total weight in pounds by the cubic feet. The result is pounds per cubic foot.
Example: a pallet 48 × 40 × 50 inches is 55.6 cubic feet. At 500 lb, the density is about 9 lb per cubic foot, which points to class 100 on the density scale.
What else affects class
Density is the main factor, but the classification also weighs handling, stowability and liability. Some commodities have a fixed class or special rules regardless of density, which is why the NMFC item for your product matters. Many items moved to a standard 13-tier density scale when the classification was updated in July 2025.
Why it matters
If the class on the bill of lading does not match what the carrier measures at its terminal, the carrier re-classes the shipment and bills the difference, usually with an inspection fee. Accurate dimensions and weight at quote time are the best protection.
| Density (lb per cubic foot) | Estimated class |
|---|---|
| 50 or more | 50 |
| 35 to under 50 | 55 |
| 30 to under 35 | 60 |
| 22.5 to under 30 | 65 |
| 15 to under 22.5 | 70 |
| 12 to under 15 | 85 |
| 10 to under 12 | 92.5 |
| 8 to under 10 | 100 |
| 6 to under 8 | 125 |
| 4 to under 6 | 175 |
| 2 to under 4 | 250 |
| 1 to under 2 | 300 |
| Under 1 | 400 |
Common questions
Do I need an NMFC number to get a quote?
No. Accurate dimensions, weight and a clear description are enough to estimate a density-based class. An NMFC item number makes the quote more reliable when your commodity has its own rules.
What is the cheapest freight class?
Class 50, which covers very dense freight of 50 lb per cubic foot or more. Class 500 is the most expensive and covers very light or high-value freight.
Does freight class apply to truckload?
No. Freight class is an LTL concept. Truckload is priced by the truck, lane and equipment.
Written by the MeritSpan Logistics team. Last reviewed November 9, 2026. Figures are typical values; equipment and carrier rules vary.