Freight class 250
Do not subtract visible air gaps from a rectangular-envelope calculation.
2 to under 4 lb/ft³
The lower boundary of 2 lb/ft³ is included. Exactly 4 lb/ft³ enters class 175.
2025 density scale. Item confirmation required.
Where this class 250 example sits
Toward class 300: 3 − 2 = 1 lb/ft³ above the cutoff. The lower edge remains included. Toward class 175: 4 − 3 = 1 lb/ft³ to the next boundary.
A bulky 300 lb handling unit occupying 100 ft³
A finished 60 × 48 × 60 in handling unit has a rectangular volume of exactly 100 ft³. With 300 lb gross weight, density is 3 lb/ft³ and the density estimate is class 250.
This calculator uses the unit’s outside rectangular envelope. Subtracting an assumed 30 ft³ of open space would produce a different denominator: 70 ft³. The resulting 4.286 lb/ft³ would no longer describe the measurement model used here.
| Scenario | Quantity × L × W × H; weight per unit | Total volume | Density | Class |
|---|---|---|---|---|
| Full outside envelope at 300 lb | 1 × 60 × 48 × 60 in at 300 lb each | 100 ft³ | 3 lb/ft³ | 250 |
| Same envelope at 200 lb | 1 × 60 × 48 × 60 in at 200 lb each | 100 ft³ | 2 lb/ft³ | 250 |
| Same envelope at 400 lb | 1 × 60 × 48 × 60 in at 400 lb each | 100 ft³ | 4 lb/ft³ | 175 |
Hypothetical measurements. Calculator Methodology.
Compare the measured scenarios
Unrounded density; rounded display labels.
Separate empty space from a smaller finished envelope
Air inside packaging or space between shapes is not automatically a deduction in this rectangular calculation. A smaller outside length, width, or height is a different measurable handling unit; an imagined internal volume deduction is not.
For irregular freight, confirm the carrier’s measurement treatment rather than assuming this simple box model applies. The example’s lower boundary is 200 lb at 100 ft³, and its next denser band starts at 400 lb. Neither number supplies a load rating or a reason to add weight.
Measure 75 ft³; do not subtract imagined air
At the same 300 lb and 60 × 48 in footprint, 45 inches gives 75 ft³ and reaches class 175. This is an actual smaller outside envelope, unlike deducting a guessed internal void.
| Boundary density | Target volume | Total height | Class at boundary |
|---|---|---|---|
| 4 lb/ft³ | 75 ft³ | 45 in | 175 |
Arithmetic target; confirm safe packaging.
Questions before you ship
Can I use the product’s occupied volume instead of the package dimensions?
Not in this calculator’s rectangular-envelope model. Use the finished outside measurements, including packaging. If the freight requires a different measurement method, obtain that method from the carrier before using the result.
Related density bands
Sources
Reviewed 2026-10-25: NMFTA scale; effective July 19, 2025; packaging margin (2026).
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