Freight Basics

Freight Class: How to Read the Code on Your Bill

Published May 29, 2026 · By Rob Eller

Freight class is the 1-to-500 number assigned under the National Motor Freight Classification (NMFC) that decides what carriers charge to haul your shipment. There are 18 classes. A single one-step reclassification — say, Class 70 bumped to Class 85 — can raise the bill by 15–25%, and it shows up on the invoice as a one-line code most shippers never check.

How freight class is determined

The NMFTA assigns every commodity a class based on four factors. Density does most of the work, but the other three can push a commodity up or down by one or two steps.

• Density — pounds per cubic foot of the packaged shipment, calculated as weight divided by length × width × height in feet.
• Stowability — how easily the freight loads next to other freight (hazmat, awkward lengths, and freight that cannot be stacked all reduce stowability).
• Handling — how much manual or special equipment effort the freight needs at terminals.
• Liability — risk of damage, theft, or damaging other freight (high-value or fragile loads carry more liability).

Density example: 800 pounds of packaged product in a pallet that measures 48 × 40 × 54 inches works out to 800 lb ÷ 60 cu ft = 13.3 lb/cu ft. That density bracket lands the shipment in Class 100 on the standard density scale.

The 18 NMFC classes and what they cost you

Below is the standard density scale with one common commodity per class and the rough rate multiplier vs. a Class 50 baseline. Carriers publish their own rate tables, so the multipliers here are directional — useful for spotting whether a reclassification is a small bump or a serious one.

Worked example: $30M LTL program, $290K–$310K recovered annually from reclass disputes

A national distributor running a $30M annual LTL program across roughly 28,000 PROs per year. Carrier reweigh-and-reclass rate averages 4.2% of shipments — about 1,180 reclassified PROs annually.

Average per-shipment variance on reclassified shipments: $385. Annual leakage from reclassification across the program: $454,300. Of that total, roughly 65% is recoverable with proper BOL evidence (declared class + density calc) and carrier-side reweigh-ticket challenges — call it $290K–$310K per year.

At enterprise scale, a $100M LTL program with the same 4.2% reclass rate has $1.5M of annual reclass leakage, of which $950K–$1.05M is recoverable. PRECISE Freight Audit's largest single-shipment recovery on record is an EDI-billed shipment over-billed by $304,447 against an actual cost of $1,423 — reclassification gone unchecked at enterprise scale.

Where carriers get it wrong (and how to catch it)

After reviewing several thousand Less-than-Truckload (LTL) reclassifications, the most common pattern is a carrier reweigh that uses a dim divisor different from what the contract specifies, and then bills the resulting class without ever sending the shipper the ticket. Five reclass triggers come up over and over:

1. Reweigh by carrier showing dim weight greater than actual. The dim calc is often miscalibrated or uses a smaller divisor than the contract allows.
2. NMFC code outdated on the BOL. The NMFTA reclassifies commodities mid-year; carriers update their tariffs before shippers update their BOL templates.
3. Density calc using gross weight, not net product. Pallet and packaging weight get added back in, which can drop density into a higher class bracket.
4. Handling factor invoked without Over, Short, and Damaged (OS&D) evidence. The carrier bumps the class for "handling" without supporting documentation.
5. Freight All Kinds (FAK) rate not honored where contract allows. The carrier bills the published NMFC class instead of the FAK class locked in by the Master Rate Agreement (MRA).

What your contract should say

Two clauses in the MRA do most of the work to keep classification disputes manageable.

FAK rate clause — locks a single class regardless of NMFC:

Reclassification dispute clause — gives you the paper trail you need to win:

Comparison: class-based rate vs. FAK rate

Six monthly LTL shipments, same lane, mixed commodities ranging from Class 60 to Class 100. Under standard class-based billing the invoice bounces month to month, and every reclass becomes a separate dispute. Under a FAK rate the same six shipments rate at Class 70 every time.

In this pattern the FAK rate runs roughly 12% lower over the year and cuts reclassification disputes to near zero, because the FAK class is contractually locked.

What we can't tell from the bill alone

The invoice line item shows the class billed and the rate applied. It almost never shows the underlying reweigh ticket, the dimensions used, or the NMFC item number with its effective date. A real classification dispute needs all four pieces of evidence:

• Original BOL with declared class and density calculation
• Carrier reweigh ticket (scale ID, time, dimensions)
• Photo evidence of the shipment in the position measured
• NMFC item number and effective date of the published class

A paper-only dispute that argues the math without producing the reweigh ticket and photos usually loses. That is why the contract clause above matters: it requires the carrier to hand you the evidence you need before they can rebill.

How Eller Audit handles this

Every PRO number gets run against the carrier's published reweigh records and the class you declared on the BOL. Where the two disagree, we flag it; where the carrier rebilled without producing the supporting reweigh ticket, we open a post-audit dispute and recover the difference under the contract dispute clause and 49 USC 13710. First audit is free, and we only get paid when you do.

FAQ