Freight Class 50 vs 55: What Changes?
Freight class 50 applies at 50+ PCF and class 55 at 35 to under 50 PCF. See how the two tiers compare after the 2025 NMFC changes.
For density-based NMFC provisions, freight class 55 applies at 35 pounds per cubic foot but less than 50 pounds per cubic foot. Freight class 50 applies at 50 pounds per cubic foot or greater.
That is the threshold difference, but density does not let a shipper choose between the two classes by itself. The correct result starts with the applicable NMFC item and subprovision for the commodity, including its packaging rules, notes, and effective date.
Class 50 and class 55 at a glance
| Comparison point | Freight class 55 | Freight class 50 |
|---|---|---|
| Full-density band | 35 to less than 50 lb/ft³ | 50 lb/ft³ or greater |
| 13-subprovision scale | Subprovision 12 | Subprovision 13 |
| Threshold question | Is packaged density at least 35 but still below 50? | Is packaged density at least 50? |
| What still must be verified | Commodity item, shipping form, packaging, notes, effective date, and applicable tariff or pricing terms | Commodity item, shipping form, packaging, notes, effective date, and applicable tariff or pricing terms |
The bands above come from NMFTA’s current full-density scale. They do not mean every commodity at that density receives class 50 or 55. NMFTA’s classification policies say the full-density scale applies when a commodity does not exhibit unusual or significant handling, stowability, or liability characteristics.
What changed in 2025
Freight classes 50 and 55 existed before the 2025 NMFC changes. What changed was the structure of the standard full-density scale.
NMFTA expanded that scale from 11 to 13 subprovisions. The current high-density end includes:
- Subprovision 11: 30 to less than 35 pounds per cubic foot, class 60
- Subprovision 12: 35 to less than 50 pounds per cubic foot, class 55
- Subprovision 13: 50 pounds per cubic foot or greater, class 50
The distinction matters because an older density chart may stop at class 60 or show a different high-density arrangement. Use current NMFC content for the shipment date instead of relying on a saved chart without an effective date.
Density is a condition, not the commodity lookup
NMFTA evaluates commodities using four transportation characteristics: density, handling, stowability, and liability. Density has prime importance when the other three do not present unusual or significant concerns. Items with such concerns may use different class provisions.
That means the process is not:
- Calculate density.
- Pick class 50 or 55.
It is:
- Identify the commodity accurately.
- Find the applicable NMFC item and shipping form.
- Read its subprovisions, notes, packaging requirements, and references.
- Calculate packaged density if the applicable provision uses density.
- Apply the density result to that provision.
- Check the effective date and any governing carrier or customer terms.
NMFTA describes the NMFC as a voluntary standard. A carrier may also publish tariff provisions or operate under customer-specific pricing terms. Those documents can affect how the shipment is rated even when the NMFC classification itself is clear.
How to calculate packaged density
Use the complete handling unit as tendered for pickup. Measure the outside length, width, and height, including the pallet, crate, wrap, and anything that projects beyond the main package. Use the weight of the complete handling unit, not only the product inside it.
For dimensions in inches:
- Multiply length by width by height to find cubic inches.
- Divide cubic inches by 1,728 to find cubic feet.
- Multiply by the number of identical handling units when appropriate.
- Divide total packaged weight in pounds by total cubic feet.
NMFTA’s ClassIT+ density calculator uses this same sequence. NMFTA also warns that its calculator is for estimation and reference and does not suggest an item’s class. The calculation supports the classification lookup; it does not replace it.
Why the 50-pound boundary requires precise inputs
The dividing line is exact. A density of 50 pounds per cubic foot meets the class 50 band on the full-density scale. A result below 50 does not, even if it is close.
Measurement shortcuts can move a result across that boundary. Common problems include:
- Measuring the product while omitting the pallet or crate
- Ignoring overhang, bulges, or projections
- Using an estimated weight instead of the packaged weight
- Combining unlike handling units as though their dimensions were identical
- Rounding intermediate measurements too early
- Using a density result from an older packaging configuration
Record the dimensions and weight used in the calculation. If the shipment is repalletized, divided, combined, or otherwise changed before pickup, calculate again and update the shipping documents.
Does class 50 always cost less than class 55?
Do not treat the class number as a complete price quote. Freight class can affect the rate basis, but the billed amount also depends on the shipment weight, lane, carrier pricing, minimum charges, discounts, fuel treatment, and requested services.
Class 50 is lower than class 55 in the NMFC class sequence. That does not establish a universal dollar difference, and it does not guarantee that one carrier’s class 50 option will cost less than another carrier’s class 55 option. Compare complete, shipment-specific quotes under the applicable terms.
Accessorial services also matter. Liftgate service, limited-access pickup or delivery, inside service, residential service, appointments, and other carrier-defined services may affect the total without changing the freight class.
How to verify which class applies
Before putting class 50 or 55 on a quote request or bill of lading, confirm each of these points:
- Commodity: The description matches what is actually shipping.
- Shipping form: The item applies to the product in its tendered form.
- NMFC item: The item number and any subitem are current and applicable.
- Density provision: The item actually uses the relevant density scale.
- Packaged measurements: Weight and outside dimensions describe the complete handling unit.
- Threshold: The unrounded result falls in the correct band.
- Packaging and notes: Required conditions and references have been reviewed.
- Effective date: The NMFC content applies on the shipment date.
- Other terms: Applicable carrier tariffs, exceptions, or pricing agreements have been checked.
ClassIT+ supports both current and historical NMFC searches. Its historical filters can search by date, supplement, or public docket. That is useful when reviewing an older quote or invoice because today’s item details may not be the version that applied when the freight moved.
If the commodity lookup remains uncertain, use qualified classification assistance rather than selecting a class from density alone. Save the lookup record with the shipment file so the declared class can be traced later.
Information to prepare for a quote
Gather the shipment facts before comparing rates:
- Origin and destination ZIP codes
- Number and type of handling units
- Outside packaged dimensions for each handling unit
- Packaged weight
- Precise commodity description
- NMFC item and freight class, when verified
- Pickup timing
- Required pickup and delivery services
This information helps distinguish a classification question from a service or rating question. It also makes competing quotes easier to compare on the same basis.
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Once the commodity, packaged dimensions, weight, freight class, lane, and required services are ready, use those details to compare the available freight options.
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