Freight Class Explained: All 18 NMFC Classes
The freight class chart (density to class)
For most commodities, density is the primary driver of class. The chart below maps density (pounds per cubic foot) to its typical class:
| Class | Density (lbs/ft³) | Typical freight |
|---|---|---|
| 50 | 50+ | Bricks, sand, nuts & bolts |
| 55 | 35-50 | Hardwood flooring, cement |
| 60 | 30-35 | Car parts, steel cable |
| 65 | 22.5-30 | Bottled beverages, books |
| 70 | 15-22.5 | Auto engines, food items |
| 77.5 | 13.5-15 | Tires, bathroom fixtures |
| 85 | 12-13.5 | Crated machinery, cast iron |
| 92.5 | 10.5-12 | Appliances, computers |
| 100 | 9-10.5 | Boat covers, canvas, wine cases |
| 110 | 8-9 | Cabinets, framed art |
| 125 | 7-8 | Small household appliances |
| 150 | 6-7 | Auto sheet metal, bookcases |
| 175 | 5-6 | Clothing, couches, stuffed furniture |
| 200 | 4-5 | Aircraft parts, aluminum tables |
| 250 | 3-4 | Mattresses, plasma TVs |
| 300 | 2-3 | Wood cabinets, tables, chairs |
| 400 | 1-2 | Deer antlers, lightweight assemblies |
| 500 | <1 | Ping pong balls, low-density bulky goods |
Why lower class costs less
LTL carriers sell trailer space. A pallet of class 50 freight (say, 1,000 lbs in 15 cubic feet) packs a lot of revenue weight into a small footprint, so the carrier earns well per cubic foot and charges a low rate per pound. A pallet of class 400 freight (say, 50 lbs filling the same 15 cubic feet) occupies the same space but carries little weight - so the per-pound rate is much higher to make the space economical.
This is why increasing density usually lowers your class and your cost. Smart packaging that reduces wasted space can move freight into a cheaper class.
When density is not the whole story
Density determines class for most general commodities, but some items are assigned a fixed class regardless of density because of stowability, handling, or liability concerns - hazardous materials, fragile electronics, and high-value goods are common examples. Always verify against the actual NMFC provision rather than assuming density alone. Use the Freight Class Calculator for a density-based estimate, then confirm with the NMFC Lookup.
Frequently asked questions
What is the lowest freight class?
Class 50 is the lowest and cheapest, used for very dense freight (50+ lbs per cubic foot).
What is the highest freight class?
Class 500 is the highest, used for very light, bulky, or high-value freight under 1 lb per cubic foot.
Does higher density mean lower freight class?
Yes. For most commodities, higher density means a lower class number and a lower shipping cost.
Related guides
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