Freight Class Explained: Density, NMFC and the 2026 Classification System

What is freight class?

Freight class is a classification used primarily in U.S. less-than-truckload shipping. The National Motor Freight Classification provides commodity descriptions and classification provisions that carriers, shippers and logistics providers can use when determining class.

How the NMFC changed

The NMFC modernization expanded the standard full-density scale to 13 subprovisions. For commodities assigned to this full-density structure, the freight class is determined from pounds per cubic foot using the applicable density range.

Current 13-sub full-density scale

• Less than 1 pcf — Class 400
• 1 but less than 2 pcf — Class 300
• 2 but less than 4 pcf — Class 250
• 4 but less than 6 pcf — Class 175
• 6 but less than 8 pcf — Class 125
• 8 but less than 10 pcf — Class 100
• 10 but less than 12 pcf — Class 92.5
• 12 but less than 15 pcf — Class 85
• 15 but less than 22.5 pcf — Class 70
• 22.5 but less than 30 pcf — Class 65
• 30 but less than 35 pcf — Class 60
• 35 but less than 50 pcf — Class 55
• 50 pcf or greater — Class 50

How freight density is calculated

For a handling unit measured in inches and pounds, multiply the greatest outside length, width and height as tendered for shipment. Divide cubic inches by 1,728 to obtain cubic feet, then divide shipment weight by cubic feet.

Worked density example

A palletized handling unit measuring 48 × 40 × 48 inches occupies approximately 53.33 cubic feet. If it weighs 500 pounds, its density is approximately 9.38 pounds per cubic foot.

Under the current standard 13-sub full-density scale, a density of 9.38 pcf falls in the 8 but less than 10 pcf range, corresponding to Class 100 for an item that actually uses the full-density scale.

Why density does not determine every freight class

The standard density scale applies to commodities that are classified under full-density provisions. Other commodities can have classification provisions influenced by characteristics beyond density.

• Handling characteristics
• Stowability
• Liability
• The applicable NMFC commodity item
• Packaging or shipping form
• Carrier-specific tariffs or rules

Why accurate dimensions matter

Density depends directly on shipment dimensions. Measurements should reflect the greatest straight-line outside dimensions of the handling unit as actually tendered to the carrier, including projections where applicable.

Freight class calculator vs official classification

A density calculator can show where a shipment's density falls on the standard 13-sub full-density reference scale. It cannot determine whether a particular commodity is governed by that scale or identify the correct NMFC item.