What Are Freight Classes?
Freight class is a standardized classification system used in Less-Than-Truckload (LTL) shipping to determine pricing. The National Motor Freight Classification (NMFC) system assigns classes from 50 to 500, with higher classes generally meaning higher shipping costs.
The Four Classification Factors
NMFC class is determined by four characteristics:
1. Density
Weight per cubic foot (lbs/cu ft). The primary factor for most products:
- Higher density = lower class = lower cost
- Calculate: Weight / (L x W x H in feet)
- Denser freight is easier and more efficient to transport
2. Stowability
How easily the freight can be stored with other goods:
- Regular shapes stow better than irregular
- Hazmat has stowability restrictions
- Oversize items affect trailer space usage
3. Handling
Special care required during transport:
- Fragile items need more careful handling
- Heavy items need equipment
- Hazardous materials require special procedures
4. Liability
Risk of damage or theft and cargo value:
- Perishable goods have higher liability
- High-value items increase carrier risk
- Damage susceptibility affects class
Freight Class Scale
| Class | Density Range | Example Products |
|---|---|---|
| 50 | 50+ lbs/cu ft | Bricks, sand, nuts/bolts |
| 55 | 35-50 lbs/cu ft | Hardwood flooring, cement |
| 60 | 30-35 lbs/cu ft | Car parts, bottled beverages |
| 65 | 22.5-30 lbs/cu ft | Car accessories, books |
| 70 | 15-22.5 lbs/cu ft | Food items, auto engines |
| 77.5 | 13.5-15 lbs/cu ft | Tires, caskets |
| 85 | 12-13.5 lbs/cu ft | Crated machinery |
| 92.5 | 10.5-12 lbs/cu ft | Computers, refrigerators |
| 100 | 9-10.5 lbs/cu ft | Furniture, wine cases |
| 110 | 8-9 lbs/cu ft | Cabinets, table saws |
| 125 | 7-8 lbs/cu ft | Small appliances |
| 150 | 6-7 lbs/cu ft | Auto sheet metal |
| 175 | 5-6 lbs/cu ft | Clothing, couches |
| 200 | 4-5 lbs/cu ft | Mattresses, aircraft parts |
| 250 | 3-4 lbs/cu ft | Bamboo furniture, plasma TVs |
| 300 | 2-3 lbs/cu ft | Wood cabinets, tables |
| 400 | 1-2 lbs/cu ft | Deer antlers |
| 500 | Less than 1 lb/cu ft | Ping pong balls, bags of feathers |
Finding Your NMFC Code
- Search the NMFC database (requires subscription)
- Ask your carrier or freight broker
- Use carrier online tools
- Consult commodity-specific guidance
Density-Based Pricing
Many carriers now use density-based pricing instead of or in addition to class:
- Actual dimensions and weight determine cost
- Reduces disputes over classification
- May be cheaper for dense freight
- Can be more expensive for light/bulky items
Reweigh and Reclassification
Carriers may inspect shipments and adjust:
- Reweigh: Verify actual weight vs. declared
- Re-dimension: Measure actual size
- Reclassification: Assign different class based on inspection
Inaccurate classification leads to additional charges. Always measure and weigh accurately.
Strategies to Lower Freight Class
Packaging Optimization
- Use smaller boxes that fit product tightly
- Reduce void fill and wasted space
- Break up large shipments into denser units
Palletization
- Stack cartons to maximize pallet density
- Don't ship partial pallets when possible
- Use appropriate pallet size for your products
Accurate Classification
- Don't guess—verify the correct NMFC code
- Some products have multiple possible classifications
- Packaging method can affect class
Understanding freight class gives you control over your LTL shipping costs. Take time to optimize packaging and ensure accurate classification.
