Freight class 55
Compact loads are sensitive to omitted base or packaging height.
35 to under 50 lb/ft³
The lower boundary of 35 lb/ft³ is included. Exactly 50 lb/ft³ enters class 50.
2025 density scale. Item confirmation required.
Where this class 55 example sits
Toward class 60: 40 − 35 = 5 lb/ft³ above the cutoff. The lower edge remains included. Toward class 50: 50 − 40 = 10 lb/ft³ to the next boundary.
A compact 320 lb unit: 24 inches versus 28 inches high
A finished 24 × 24 × 24 in handling unit occupies 8 ft³. At 320 lb gross weight, its density is 40 lb/ft³ and the density-scale estimate is class 55.
If 24 in was the product height and the finished unit is actually 28 in tall, volume becomes about 9.333 ft³. At the same measured gross weight, density drops to about 34.286 lb/ft³: class 60. The extra four inches are small in absolute terms but large relative to this compact unit.
| Scenario | Quantity × L × W × H; weight per unit | Total volume | Density | Class |
|---|---|---|---|---|
| Recorded as a 24 in cube | 1 × 24 × 24 × 24 in at 320 lb each | 8 ft³ | 40 lb/ft³ | 55 |
| Finished height is 28 in | 1 × 24 × 24 × 28 in at 320 lb each | 9.333 ft³ | 34.286 lb/ft³ | 60 |
| 24 in cube weighing 400 lb | 1 × 24 × 24 × 24 in at 400 lb each | 8 ft³ | 50 lb/ft³ | 50 |
Hypothetical measurements. Calculator Methodology.
Compare the measured scenarios
Unrounded density; rounded display labels.
Small dimensions do not excuse missing packaging
Use the actual outside envelope and gross weight together. Do not pair bare-product dimensions with a weight that already includes a base or crate; that combination overstates density.
For the original 8 ft³ envelope, class 55 begins at 280 lb and ends just below 400 lb. Exactly 400 lb gives 50 lb/ft³ and enters class 50. These are arithmetic thresholds for this envelope, not a rated capacity for any pallet or package.
A shallower envelope would reach class 50
Holding the 320 lb weight and 24-inch square footprint fixed gives a 19.2-inch height at the next threshold. That is a different package from the 400 lb cube in the table.
| Boundary density | Target volume | Total height | Class at boundary |
|---|---|---|---|
| 50 lb/ft³ | 6.4 ft³ | 19.2 in | 50 |
Arithmetic target; confirm safe packaging.
Questions before you ship
Does a dense class 55 unit automatically have a low shipping rate?
No. This example only establishes a density-band estimate. It supplies no freight price, packing approval, liability assessment, or item-specific class. Use the applicable item rules and the carrier’s quote.
Related density bands
Sources
Reviewed 2026-10-25: NMFTA scale; effective July 19, 2025; packaging margin (2026).
Last updated