under 1 pcf · NMFC density scale

Freight class 400

The rating for freight at under 1 pounds per cubic foot on the current 13-band NMFC density scale. Typically bagged insulation and other extremely light freight.

What ships at class 400

Class 400 is the top of the current density scale, for freight under 1 pcf. Class 500 is not on the scale at all, though an older density guideline mapped sub-1 pcf freight to it - which is why some free calculators still return 500 for very light freight. We tested that: see the calculator audit.

Worked example. A standard pallet: 48 × 40 × 48 in, 40 lb. That is 53.3 cu ft and 40 lb → 0.75 pcf → class 400. Run your own numbers →

Where class 400 sits on the scale

Freight class runs from 50 (densest, cheapest per pound) to 400 on the current density scale. Class 400 is band 13 of 13.

Either side of this band: denser freight (1 - 2 pcf) rates class 300, which is cheaper.

The full table is on the freight class chart, and the calculator works out density and class from your dimensions, including multi-pallet shipments.

Density is the default, not the whole rule. Since Docket 2025-1 most commodities class by density, but items with unusual stowability, handling or liability characteristics can class differently. Confirm the NMFC item before the BOL goes out.