Determine LTL freight class (NMFC) including density-based classification under the 2025 updates

Verified steps

1. Measure the shipment: obtain precise gross weight (lbs), and dimensions of the tightest rectangular bounding box (length × width × height in inches) for each handling unit.
2. Calculate density: divide weight in pounds by volume in cubic feet (volume = L × W × H / 1728); this is the primary classification input under the July 19, 2025 NMFTA Docket 2025-1 changes which expanded the density scale from 11 to 13 classes (adding classes 50 and 55).
3. Look up the density in the current NMFC density-class table to determine freight class; classes range from 50 (densest, cheapest) to 500 (lightest, most expensive); use NMFTA's ClassIT+ tool or a licensed tariff database for authoritative lookup.
4. For commodity items that retain a specific NMFC item number (not yet converted to density-based), look up that item number in the NMFC to obtain the applicable class regardless of density.
5. Apply the correct freight class to the BOL and rate request; carriers will re-weigh and re-measure at their dock — if their measurement differs from yours, they will reclassify and issue a freight bill correction (NFMC inspection report).
6. Audit carrier reweigh/reclassification notices against your original measurements; dispute via the carrier's claims process if you have documented evidence that your measurements are correct.