Freight class 50
Class 50 has a lower density boundary and no next denser tier.
50 and above lb/ft³
The lower boundary of 50 lb/ft³ is included. There is no upper density limit or next denser tier in this table.
2025 density scale. Item confirmation required.
Where this class 50 example sits
Toward class 55: 60 − 50 = 10 lb/ft³ above the cutoff. The lower edge remains included. No denser tier.
A 300 lb compact unit at the top of the density scale
A finished handling unit measuring 24 × 20 × 18 in occupies exactly 5 ft³. With 300 lb gross weight, it has a density of 60 lb/ft³ and falls in class 50.
This band continues upward without another density threshold. Increasing density from 60 to 70 does not produce a new class in this table, and the calculator correctly shows no next class boundary. That does not establish that freight rates stay fixed or that the item uses this scale.
| Scenario | Quantity × L × W × H; weight per unit | Total volume | Density | Class |
|---|---|---|---|---|
| Finished unit at 18 in high | 1 × 24 × 20 × 18 in at 300 lb each | 5 ft³ | 60 lb/ft³ | 50 |
| Same footprint, 20 in high | 1 × 24 × 20 × 20 in at 300 lb each | 5.556 ft³ | 54 lb/ft³ | 50 |
| Same footprint, 22 in high | 1 × 24 × 20 × 22 in at 300 lb each | 6.111 ft³ | 49.091 lb/ft³ | 55 |
Hypothetical measurements. Calculator Methodology.
Compare the measured scenarios
Unrounded density; rounded display labels.
The lower edge still matters
For this 300 lb example, a volume of 6 ft³ gives exactly 50 lb/ft³. At the 24 × 20 in footprint, that corresponds to 21.6 in of total height. A finished height above 21.6 in moves below the class 50 density threshold.
The 22 in version is about 49.091 lb/ft³, so rounding it to 50 would give the wrong lookup. Measure the completed handling unit and use the unrounded result; do not assume a compact heavy article always remains in class 50.
There is no lower class number to reach here
This calculation instead finds the tallest envelope that retains 50 lb/ft³. The original 18 inches can grow to 21.6 inches before crossing below the class 50 threshold.
| Boundary density | Target volume | Total height | Class at boundary |
|---|---|---|---|
| 50 lb/ft³ | 6 ft³ | 21.6 in | 50 |
Arithmetic target; confirm safe packaging.
Questions before you ship
Why is there no distance to the next class above class 50?
Class 50 is the final, open-ended band of this density scale, starting at 50 lb/ft³. There is no higher-density row to reach. You can still calculate the margin above its lower boundary.
Related density bands
Sources
Reviewed 2026-10-25: NMFTA scale; effective July 19, 2025; packaging margin (2026).
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