What is Freight Class?

What is Freight Class?

Freight class is a standardized classification system used by LTL (Less-Than-Truckload) carriers to price shipments. Managed by the National Motor Freight Traffic Association (NMFTA), the National Motor Freight Classification (NMFC)system assigns every commodity a class from 50 to 500.

The class determines the shipping rate: lower classes (50-70) are denser and cheaper to ship, while higher classes (300-500) are lighter, bulkier, or harder to handle-and more expensive.

Getting freight class wrong can result in carrier reweighs, reclassifications, and unexpected charges that add 20% or more to your shipping costs.

The Four Classification Factors

Freight class is determined by four characteristics, with density being the most important:

1. Density

Density is weight per cubic foot (lbs/ft³). It's the primary factor because carriers sell truck space-denser freight generates more revenue per cubic foot.

Formula: Density = Weight (lbs) ÷ Volume (ft³)

Example: A 500 lb pallet measuring 4' × 4' × 4' = 64 cubic feet
Density = 500 ÷ 64 = 7.8 lbs/ft³ → Class 125

2. Stowability

How easily does the freight fit with other cargo? Factors include:

• Odd shapes that waste space
• Hazardous materials requiring isolation
• Length exceeding standard dimensions
• Floor-loaded vs. palletized goods

3. Handling

Does the freight require special handling? Considerations:

• Fragile items requiring extra care
• Heavy items needing equipment
• Awkward shapes difficult to move
• Temperature-sensitive goods

4. Liability

What's the risk of damage, theft, or causing damage to other freight?

• High-value items (electronics, jewelry)
• Perishable goods
• Hazardous materials
• Items prone to damage

The 18 Freight Classes

Here are all 18 NMFC freight classes with their density ranges and examples:

Low Classes (Dense, Cheaper)

• Class 50: >50 lbs/ft³ - Sand, bricks, cement
• Class 55: 35-50 lbs/ft³ - Steel, hardwood flooring
• Class 60: 30-35 lbs/ft³ - Car parts, steel rods
• Class 65: 22.5-30 lbs/ft³ - Beverages, tile
• Class 70: 15-22.5 lbs/ft³ - Food items, machinery
• Class 77.5: 13.5-15 lbs/ft³ - Tires, bathroom fixtures
• Class 85: 12-13.5 lbs/ft³ - Crated machinery, cast iron
• Class 92.5: 10.5-12 lbs/ft³ - Computers, motors
• Class 100: 9-10.5 lbs/ft³ - Boat covers, car covers

Mid Classes

• Class 110: 8-9 lbs/ft³ - Cabinets, table saws
• Class 125: 7-8 lbs/ft³ - Small appliances, books
• Class 150: 6-7 lbs/ft³ - Auto sheet metal, bookcases
• Class 175: 5-6 lbs/ft³ - Clothing, couches
• Class 200: 4-5 lbs/ft³ - Auto parts, aluminum tables

High Classes (Light/Bulky, More Expensive)

• Class 250: 3-4 lbs/ft³ - Mattresses, bamboo furniture
• Class 300: 2-3 lbs/ft³ - Wood cabinets, chairs
• Class 400: 1-2 lbs/ft³ - Deer antlers, ping pong balls
• Class 500: <1 lb/ft³ - Bags of gold, ping pong balls

How to Determine Your Freight Class

Option 1: Use Density Calculation

For most commodities, you can calculate class based on density:

1. Measure the dimensions of your shipment (length × width × height in inches)
2. Convert to cubic feet: (L × W × H) ÷ 1,728
3. Divide total weight by cubic feet = density
4. Match density to the appropriate class range

Option 2: Look Up NMFC Code

Many commodities have assigned NMFC codes with predetermined classes regardless of density. Examples:

• Furniture (NOI): NMFC 100860, Class varies by type
• Electronics: Various NMFC codes by product type
• Machinery: NMFC 133500, Class based on weight/dimensions

Option 3: FAK (Freight All Kinds)

Some carriers offer FAK rates-flat class rates regardless of commodity. This simplifies classification but may cost more for dense freight.

How Freight Class Affects Costs

Freight class has a significant impact on LTL shipping costs:

Rate Calculation

LTL rates are typically quoted as "price per hundred pounds" (cwt) by class. Higher classes have higher per-cwt rates.

Example: Shipping 500 lbs, 750 miles

• Class 70: $15/cwt = $75 base rate
• Class 125: $25/cwt = $125 base rate
• Class 200: $40/cwt = $200 base rate

Moving from Class 70 to Class 125 nearly doubles the cost!

Reweighs and Reclassifications

Carriers audit shipments. If your freight is heavier or lower-density than declared:

• Carrier applies correct class and rebills
• Reweigh fees may apply ($25-75)
• Unexpected charges arrive weeks later

Tips for Shippers

1. Weigh and measure accurately: Use calibrated scales and measure every piece. Don't estimate.
2. Calculate density for each shipment: Even for the same product, different quantities may change the class.
3. Know your NMFC codes: Look up specific codes for your commodities in the NMFC database.
4. Consider repackaging: Sometimes adjusting packaging dimensions can improve density and lower class.
5. Negotiate FAK rates: If you ship regularly, negotiate FAK agreements for simpler, predictable pricing.
6. Use TMS software: Transportation management systems like SupplySense 360 can automatically calculate class and flag potential issues.
7. Document everything: Keep photos, weight tickets, and measurements to dispute incorrect reclassifications.

Conclusion

Freight class is fundamental to LTL shipping costs. Understanding how the NMFC classification system works-and accurately classifying your freight-prevents surprise charges and enables better rate comparisons between carriers.

When in doubt, measure precisely, calculate density, and verify your classification before shipping. The effort upfront saves money and headaches down the road.