Before using the Saia shipment workflow
Measure the outside of the finished handling unit, not the unpacked product. Include pallet edges and any overhang. Enter the total gross weight. This tool returns a standard density-band estimate; it does not query Saia, retrieve an NMFC item, or produce a freight quote. Handling, stowability, liability, and commodity provisions can affect the applicable class.
Read the boundary before rounding
The lower density limit belongs to its band; the upper limit belongs to the next band. Selection uses the unrounded density. The displayed figure is rounded to two decimals, so a display near a boundary is not evidence that the threshold was reached. The reverse check prints inequalities and extra decimals rather than presenting a rounded dimension as an exact cutoff.
For the default shipment, 400 lb over a 48 × 40 in footprint at 60 in packed height gives 6 lb/ft³. At 61 in, the same load falls below 6 lb/ft³. The class estimate changes from 125 to 175 on this standard scale. The height is the finished measurement; it is not a value to adjust on paperwork.
Check both excluded endpoints
For this 400 lb load on a 48 × 40 in footprint, the Class 125 height interval is greater than 45 in and at most 60 in. At exactly 45 in, density is 8 lb/ft³ and the estimate is Class 100, so that endpoint is excluded.
Keeping the 48 × 40 × 60 in envelope, Class 125 requires at least 400 lb but less than 533⅓ lb. At exactly 533⅓ lb, density reaches 8 lb/ft³ and the estimate becomes Class 100.
Scale and calculation basis
Uses the standard thirteen-subprovision density scale from NMFC Docket 2025-1, effective July 19, 2025. The scale was checked October 18, 2026 against NMFTA’s published density breaks and is the same scale used by this site’s class chart. This is not a Saia-specific tariff or a complete classification rule.
- Volume in ft³ = length × width × height in inches ÷ 1,728.
- Density in lb/ft³ = gross pounds ÷ volume in ft³.
- 1 inch = 2.54 cm; 1 pound = 0.45359237 kg; 1 foot = 0.3048 m.
- Density in kg/m³ = density in lb/ft³ × 0.45359237 ÷ 0.3048³.
- At fixed volume V and target density [a, b), weight is in [aV, bV). At fixed weight W and footprint A in square inches, height is greater than 1,728W/(Ab) and at most 1,728W/(Aa). An open-ended band has no finite limit on that side.
Questions about the result
Does this tell me what Saia will charge?
No. It produces density and a standard class estimate only. It does not calculate charges, discounts, or transit times.
What happens when I switch units?
The measurements are converted, not relabeled. Switching either unit recalculates both density outputs and the reverse-check limits for the same physical shipment.
Why can a class be different from the density estimate?
A commodity may use an item-specific provision rather than this standard density scale. An item number and a density figure describe different things.