If you ship LTL, freight class is the single most important factor determining what you pay. Misclassifying your freight can result in reclassification fees, unexpected charges, and strained carrier relationships. This guide explains how the NMFC freight classification system works and how to get it right.
What Is Freight Class?
The National Motor Freight Classification (NMFC) system assigns every commodity a freight class between 50 and 500. The system is managed by the National Motor Freight Traffic Association (NMFTA) and is used by virtually all LTL carriers in the United States to standardize pricing.
Lower freight classes mean lower shipping rates. Class 50 freight is the cheapest to ship per hundredweight; class 500 is the most expensive. The class your freight falls into depends on four factors.
The Four Classification Factors
- Density (weight per cubic foot): The most important factor. Heavier, more compact freight earns lower classes. A pallet of steel bolts (40+ lbs/ft³) qualifies for class 50, while a pallet of ping pong balls (1–2 lbs/ft³) might be class 400.
- Stowability: How easily the freight fits with other shipments on a trailer. Irregularly shaped, hazardous, or oversized items score poorly and push toward higher classes.
- Handling: The care and effort required to load, transport, and unload the freight. Items needing special equipment, orientation, or delicate handling receive higher classes.
- Liability: The risk of damage, spoilage, or theft. High-value, fragile, or perishable goods carry higher liability ratings and higher classes.
All 18 Freight Classes
Here are all 18 NMFC freight classes with typical commodity examples and density ranges:
| Class | Density (lbs/ft³) | Example Commodities |
|---|---|---|
| 50 | 50+ | Sand, gravel, steel, nuts/bolts |
| 55 | 35–50 | Bricks, hardwood flooring, cement |
| 60 | 30–35 | Car parts, car accessories, bottled beverages |
| 65 | 22.5–30 | Auto parts, bottled drinks, canned goods |
| 70 | 15–22.5 | Food items, auto parts, machinery |
| 77.5 | 13.5–15 | Tires, bathroom fixtures, garments |
| 85 | 12–13.5 | Crated machinery, cast iron stoves |
| 92.5 | 10.5–12 | Computers, monitors, refrigerators |
| 100 | 9–10.5 | Boat covers, car covers, canvas |
| 110 | 8–9 | Cabinets, framed artwork, table saws |
| 125 | 7–8 | Small household appliances, vending machines |
| 150 | 6–7 | Auto sheet metal, bookcases |
| 175 | 5–6 | Clothing, couches, stuffed furniture |
| 200 | 4–5 | Auto sheet metal parts, mattresses |
| 250 | 3–4 | Bamboo furniture, mattresses and box springs |
| 300 | 2–3 | Wood cabinets, tables, chairs (KD) |
| 400 | 1–2 | Deer antlers, ping pong balls |
| 500 | <1 | Gold dust, bags of feathers, styrofoam |
How to Calculate Freight Density
Density is calculated by dividing the total weight of your shipment by its total cubic volume:
Volume = (Length × Width × Height in inches) / 1,728
For example: A pallet measuring 48" × 40" × 48" weighing 1,200 lbs has a volume of (48 × 40 × 48) / 1,728 = 53.3 cubic feet. Density = 1,200 / 53.3 = 22.5 lbs/ft³, which falls into class 65.
Reclassification and Re-weigh Risks
LTL carriers have the right to inspect, re-weigh, and re-measure freight at their terminals. If your shipment does not match the class listed on the bill of lading, the carrier will reclassify it and adjust the charge — almost always upward. Common triggers for reclassification:
- Actual weight exceeds the weight stated on the BOL
- Dimensions are larger than described, resulting in lower actual density
- The commodity description is vague or inaccurate
- Using a “FAK” (Freight All Kinds) rate when the commodity does not qualify
Tips to Avoid Classification Problems
- Weigh and measure every shipment before it ships — do not estimate
- Use accurate commodity descriptions on the BOL (reference the NMFC code if possible)
- When in doubt, use the NMFC ClassIT tool or consult your broker for classification guidance
- Consider density-based pricing agreements with your carriers if your freight consistently falls into predictable density ranges
- Keep photos of your palletized freight as evidence in case of disputes
Getting freight class right saves money and headaches. If you are unsure about your commodity's classification, reach out to our team and we will help you classify it correctly before shipping.