LTL fundamentals

What is freight class?

A shared vocabulary for pricing. Rather than every carrier inventing its own way to price every commodity, US less-than-truckload freight is sorted into rating categories from 50 to 500 — and a shipment’s number is one of the biggest inputs into what it costs to move.

The basic idea

An LTL trailer carries freight from many shippers at once. The carrier is selling trailer space and the ability to handle what goes in it. Two pallets of the same weight can be wildly different propositions: one fits neatly in a corner and stacks, the other is fragile, oversized and blocks a bay.

Freight class is how that difference gets priced consistently. It comes from the National Motor Freight Classification, maintained by NMFTA. Lower classes are cheaper per pound; higher classes are more expensive per pound.

Counter-intuitively, heavy dense freight gets the cheap classes. A pallet of bricks is class 50. A pallet of foam insulation is class 400. The bricks weigh far more but consume far less of what the carrier is actually selling, which is space.

The four factors

  • Density — pounds per cubic foot. The dominant factor, and since July 2025 the sole factor for a much larger share of commodities.
  • Stowability — how well it loads alongside other freight. Non-stackable, oversized or hazardous items cost space the carrier cannot resell.
  • Handling — whether standard forklifts and docks move it without special care.
  • Liability — value per pound, fragility and theft risk, which set the carrier’s exposure if something goes wrong.

For most freight today, working out the density gets you the class. The other three explain the exceptions.

Why the scale changed in 2025

For most of a century the classification leaned on commodity descriptions: find your product in the book, read its class. That produced thousands of listings, a lot of ambiguity, and a lot of disputes.

NMFC Docket 2025-1, effective 19 July 2025, was the largest overhaul in decades. Around 2,000 commodity listings moved to density-based classification, and the density scale itself went from 11 sub-provisions to 13: sub 11 was narrowed to 30–35 pcf at class 60, and new sub-provisions added class 55 for 35–50 pcf and class 50 for 50 pcf and over. Docket 2026-1 continued the cleanup in February 2026. Note that classes 77.5, 110, 150, 200 and 500 are not on the density scale — older charts that produce them predate the current sub-provision structure.

The practical effect for a shipper: your class is now more predictable and more measurable, and it depends more than ever on measuring your pallets honestly.

How class becomes a rate

Class is an input, not the price. A typical LTL rate is built from the class, the weight break, the origin and destination pair, the carrier’s base tariff and your negotiated discount, plus fuel and accessorials such as liftgate, residential delivery or inside pickup.

Two shipments at class 70 on the same lane can price very differently once weight breaks and discounts apply. But move one of them to class 125 and it will cost noticeably more regardless.

Where shippers lose money. Not usually by choosing the wrong class deliberately, but by tendering dimensions and weights that do not match what the terminal scanner reads. The correction arrives as a reclass or reweigh charge on top of the recalculated rate.

Work out your class →
How NMFC item numbers relate to class →