Freight class 400
The least-dense band still requires a positive measured gross weight.
Under 1 lb/ft³
A positive density below 1 lb/ft³ falls in this band. Zero weight or volume is invalid. Exactly 1 lb/ft³ enters class 300.
2025 density scale. Item confirmation required.
Where this class 400 example sits
No lower-density class; zero is invalid. Toward class 300: 1 − 0.75 = 0.25 lb/ft³ to the next boundary.
A light packaged unit at 0.75 lb/ft³
Consider a hypothetical light, fully packaged handling unit measuring 48 × 48 × 72 in and weighing 72 lb in total. Its volume is 96 ft³, giving 0.75 lb/ft³ and class 400 on this scale.
The stated 72 lb includes every part of that handling unit. It is not an assumed weight for a wooden pallet or permission to omit a platform’s weight. This low-density example is useful for understanding the bottom of the density table without assigning any commodity to it.
| Scenario | Quantity × L × W × H; weight per unit | Total volume | Density | Class |
|---|---|---|---|---|
| Complete unit at 72 lb | 1 × 48 × 48 × 72 in at 72 lb each | 96 ft³ | 0.75 lb/ft³ | 400 |
| Same envelope at 95 lb | 1 × 48 × 48 × 72 in at 95 lb each | 96 ft³ | 0.99 lb/ft³ | 400 |
| Same envelope at exactly 96 lb | 1 × 48 × 48 × 72 in at 96 lb each | 96 ft³ | 1 lb/ft³ | 300 |
Hypothetical measurements. Calculator Methodology.
Compare the measured scenarios
Unrounded density; rounded display labels.
Zero is missing input, not a class 400 shipment
A zero weight or zero dimension cannot describe a valid density estimate here and is rejected. Any valid positive density below 1 belongs to this lowest-density band. At exactly 1, move to class 300.
The separate legacy 18-class guideline uses class 500 below 1 lb/ft³. This current scale uses class 400. The difference is a chart comparison, not a claim that every older class 500 item now has a particular contracted class.
A 54-inch envelope reaches the first positive boundary
At 72 lb and the 48-inch square footprint, 54 inches gives 72 ft³ and 1 lb/ft³: class 300. No invalid zero-weight input is involved in this comparison.
| Boundary density | Target volume | Total height | Class at boundary |
|---|---|---|---|
| 1 lb/ft³ | 72 ft³ | 54 in | 300 |
Arithmetic target; confirm safe packaging.
Questions before you ship
Is class 500 included in this density scale?
No. The 13-tier scale shown here uses class 400 for positive density below 1 lb/ft³. Class 500 appears in the separate legacy 18-class guideline; item-specific classification must still be checked.
Related density bands
Sources
Reviewed 2026-10-25: NMFTA scale; effective July 19, 2025; packaging margin (2026).
Legacy charts: Direct Drive Logistics and FML Freight; comparison conventions.
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