🚛 Freight Class Calculator

What freight class means

Freight class is a standardized rating system (the NMFC, or National Motor Freight Classification) used by LTL (less-than-truckload) carriers to price shipments. For most general commodities, class is determined primarily by density — how much a shipment weighs relative to the space it occupies — with denser shipments getting a lower class number and lower rates.

How this calculator works

Enter your shipment’s total weight, its length, width, and height, and the number of identical pieces. The calculator first computes total cubic feet: (length × width × height × pieces) ÷ 1728 (converting cubic inches to cubic feet). It then divides weight by cubic feet to get density in pounds per cubic foot, and matches that density against the standard density-based freight class table (for example, 50+ lb/ft³ is class 50, while under 1 lb/ft³ is class 300+).

• This estimate applies to density-based commodities; some items have a fixed NMFC class regardless of density (fragile, hazardous, or high-value goods, for instance).
• Always confirm the exact NMFC code and class with your carrier or a licensed freight classification lookup before booking a shipment, since misclassification can result in reweigh/reclass fees.

This tool is for general shipping-cost planning and educational purposes only.