The change covered by this guide
The NMFC changes effective July 19, 2025 expanded the standard density scale from 11 tiers to 13. The dense end includes class 55 from 35 to under 50 lb/ft³ and class 50 at 50 lb/ft³ and above. See the NMFTA carrier guide published April 14, 2025, the June 19 density guide, and NMFTA’s effective-date confirmation (checked October 25, 2026).
This site implements that dated 13-tier table. It does not track every subsequent docket or provide a live item database. The current rule for a particular commodity must be checked separately.
Do not confuse the three tables
- The 13-tier scale: the density table used by this calculator.
- The former 11-tier density scale: the table expanded in the 2025 change.
- The legacy 18-class guideline: a separate general chart still useful for explaining why older calculators can produce different answers.
Our comparison chart shows the 13-tier scale beside the legacy 18-class guideline. It does not label the 18-class table as the former 11-tier scale.
What to check in an existing shipment profile
- The physical inputs. Are dimensions and weight for the packaged handling unit, or only the product?
- The source of the saved class. Was it a carrier-confirmed classification, an old estimate, or a default field?
- The applicable item. Ask the carrier or consult ClassIT+ for current provisions and any packaging conditions.
- The table used by your software. A familiar class number does not prove that the software uses the correct boundaries.
- The next shipment documents. Use the confirmed classification consistently when requesting a quote and preparing the shipment.
A practical software check
Use a simple test shipment with 1 ft³ of volume and 8 lb of packaged weight. Density is exactly 8 lb/ft³. The 13-tier table gives class 100; the legacy 18-class guideline gives class 110.
This test identifies a difference between the tables. It does not establish that the table applies to your actual commodity. Also check exact boundaries such as 35 and 50 lb/ft³ when reviewing a calculator.
What this guide deliberately leaves to the source
Item descriptions, item numbers, exceptions, packaging provisions, and later amendments belong in the current licensed classification resources. They are not reproduced here. Our tool provides density arithmetic and a general scale lookup.
Calculate an estimated class and read the methodology for the scope of that result.
Sources & scope
Reviewed October 25, 2026. Density scale effective July 19, 2025.