FreightDock Math is independently developed. The tools use documented formulas and stated assumptions; no external professional review is claimed.
How the calculations work
FreightDock Math uses mathematical formulas and rule sets documented on the relevant calculator pages. Where a result depends on commodity classification, carrier tariffs, accessorial rules, or other external requirements, the result should be treated as an estimate unless the applicable rule has been independently confirmed.
Independent resource
FreightDock Math is not a carrier, freight broker, engineering consultancy, or official NMFTA service. It does not issue certified freight classifications, carrier quotes, tariff rulings, or engineering approvals. No external professional review is claimed.
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1. Primary Density Mathematical Proof & Derivations
In North American commercial transportation, freight density is quantified in Pounds Per Cubic Foot (PCF). While the underlying arithmetic is elementary, real-world terminal disputes emerge from measurement discrepancies at the packaging boundary. Under NMFC Item 110 § 2, the exact mathematical algorithm enforced by motor carriers is derived as follows:
Under the standardized density-based freight-class reference scale, the calculated PCF is matched against discrete subprovisions. The table below represents the mathematical boundary conditions implemented in the FreightDock Math computational core:
| Subprovision | Continuous Density Interval | Freight Class | Mathematical Bound |
|---|---|---|---|
| Subprovision 1 | 0.00 ≤ PCF < 1.00 | Class 400 | Open right interval [0, 1.0) |
| Subprovision 2 | 1.00 ≤ PCF < 2.00 | Class 300 | Closed left [1.0, 2.0) |
| Subprovision 3 | 2.00 ≤ PCF < 4.00 | Class 250 | Closed left [2.0, 4.0) |
| Subprovision 4 | 4.00 ≤ PCF < 6.00 | Class 175 | Closed left [4.0, 6.0) |
| Subprovision 5 | 6.00 ≤ PCF < 8.00 | Class 125 | Closed left [6.0, 8.0) |
| Subprovision 6 | 8.00 ≤ PCF < 10.00 | Class 100 | Closed left [8.0, 10.0) |
| Subprovision 7 | 10.00 ≤ PCF < 12.00 | Class 92.5 | Closed left [10.0, 12.0) |
| Subprovision 8 | 12.00 ≤ PCF < 15.00 | Class 85 | Closed left [12.0, 15.0) |
| Subprovision 9 | 15.00 ≤ PCF < 22.50 | Class 70 | Closed left [15.0, 22.5) |
| Subprovision 10 | 22.50 ≤ PCF < 30.00 | Class 65 | Closed left [22.5, 30.0) |
| Subprovision 11 | 30.00 ≤ PCF < 35.00 | Class 60 | Closed left [30.0, 35.0) |
| Subprovision 12 | 35.00 ≤ PCF < 50.00 | Class 55 | Closed left [35.0, 50.0) |
| Subprovision 13 | PCF ≥ 50.00 | Class 50 | Unbounded right [50.0, ∞) |
2. NMFTA Docket Modernization Background (2025–2026)
In January 2025, the National Motor Freight Traffic Association (NMFTA) initiated its most sweeping overhaul of freight classification since the deregulation era of the Motor Carrier Act of 1980. Historically, freight classification evaluated four distinct transportation characteristics: Density, Handling, Stowability, and Liability.
However, the widespread deployment of automated dimensioning systems at carrier breakbulk terminals created acute operational friction with subjective characteristics (such as whether a commodity was "difficult to handle" or "susceptible to pilferage"). Through Dockets 2025-1, 2025-2, and 2026-1, the NMFTA standardized freight classification on a quantifiable, density-first protocol, eliminating subjective commodity descriptions and phasing out confusing fractional classes (Classes 77.5, 110, 150, 200, and 500).
3. Commercial Dimensioning Reference Standards (ASTM & OIML)
Commercial dimensioning systems and freight packaging guidelines commonly reference operational specifications such as:
- OIML R 129: International Organization of Legal Metrology standard for multi-dimensional measuring instruments.
- NCWM / NIST Handbook 44: National Institute of Standards and Technology specifications for commercial weighing and measuring devices (Section 5.58: Multiple Dimension Measuring Devices).
- Measurement Tolerance: Commercial dimensioners typically operate with an allowable commercial tolerance around ±0.5 inches on an axis. In our planning tools, measured overhang exceeding 0.5 inches is flagged as a potential planning consideration.
4. Industrial & Regulatory References
Common industry reference materials and regulatory publications include:
- NMFC Tariff Series: National Motor Freight Classification NMFC 100-AW and subsequent supplements (Item 110: Definition of Shipments; Item 640: Mixed Shipments).
- ASTM D3951: Standard Practice for Commercial Packaging (dimensional tolerances, strapping retention, pallet overhang prevention).
- Federal Motor Carrier Safety Administration (FMCSA): Title 49 CFR § 393 (Parts and Accessories Necessary for Safe Operation: Cargo Securement and Weight Distribution).
- US DOT Federal Bridge Formula: 23 CFR § 658.17 (Gross Combined Vehicle Weights and Axle Loadings).
5. Contact FreightDock Math
For questions regarding calculator functionality, formula assumptions, or page corrections, please visit our Contact Page or email desk@freightdockmath.com.