If you ship LTL (less-than-truckload) freight, freight class decides what you pay — and getting it wrong is one of the most common, most expensive mistakes in shipping. This guide explains what freight class is, how to calculate it from density in three steps, and how to keep carriers from reclassifying your freight after pickup.
What is freight class?
Freight class is a standardized rating system used by LTL carriers across North America to price freight consistently. It comes from the National Motor Freight Classification (NMFC), maintained by the NMFTA. Every commodity is assigned a class between 50 and 500: the lower the class, the denser and easier to handle the freight — and the cheaper it is to ship. A pallet of bricks might rate class 50; a pallet of ping-pong balls can rate class 500.
Class is determined by four transportation characteristics:
- Density — pounds per cubic foot. The dominant factor for most freight today.
- Stowability — how well it loads with other freight (odd shapes, hazmat restrictions).
- Handling — ease of loading and unloading.
- Liability — value, fragility, theft risk, perishability.
Step 1: Calculate your shipment's density
Measure the length, width and height of the shipment in inches — as it ships, pallet and packaging included, at the tallest, widest points. Then weigh it, packaging and pallet included.
- Cubic feet = (Length × Width × Height in inches) ÷ 1,728
- Density = Weight in pounds ÷ Cubic feet
Example: a standard 48″ × 40″ pallet loaded to 48″ high weighing 500 lb: 48 × 40 × 48 = 92,160 in³ ÷ 1,728 = 53.3 ft³. Density = 500 ÷ 53.3 = 9.4 lb/ft³ → class 100 on a density basis.
Step 2: Read the freight class density chart
For density-rated commodities, this is the standard mapping used across the industry:
| Density (lb per cubic foot) | Freight class |
|---|---|
| 50 lb/ft³ or more | Class 50 |
| 35 – 49.99 lb/ft³ | Class 55 |
| 30 – 34.99 lb/ft³ | Class 60 |
| 22.5 – 29.99 lb/ft³ | Class 65 |
| 15 – 22.49 lb/ft³ | Class 70 |
| 13.5 – 14.99 lb/ft³ | Class 77.5 |
| 12 – 13.49 lb/ft³ | Class 85 |
| 10.5 – 11.99 lb/ft³ | Class 92.5 |
| 9 – 10.49 lb/ft³ | Class 100 |
| 8 – 8.99 lb/ft³ | Class 110 |
| 7 – 7.99 lb/ft³ | Class 125 |
| 6 – 6.99 lb/ft³ | Class 150 |
| 5 – 5.99 lb/ft³ | Class 175 |
| 4 – 4.99 lb/ft³ | Class 200 |
| 3 – 3.99 lb/ft³ | Class 250 |
| 2 – 2.99 lb/ft³ | Class 300 |
| 1 – 1.99 lb/ft³ | Class 400 |
| Less than 1 lb/ft³ | Class 500 |
Note: the NMFC has been moving more commodities to pure density-based classing, but many items still carry commodity-specific rules where stowability, handling or liability override density. When in doubt, confirm the NMFC item number with your carrier or broker — guessing is what generates reclass bills.
Step 3: Find the NMFC item number
Density gets you close, but LTL carriers rate against the specific NMFC item number for your commodity — “machine parts, boxed” and “machined castings” are different items with different rules. The item number goes on your Bill of Lading next to the class. A shipment with a correct NMFC number and class almost never gets re-billed; a BOL that just says “freight, class 70” invites inspection.
What happens if you get freight class wrong
- Reclassification fees. Carriers weigh and dimension freight at the terminal. If your stated class is too low, they re-bill at the correct class — plus an inspection fee.
- Invoice disputes and delays. Reclass invoices arrive weeks later and are hard to fight without photos and certified scale tickets.
- Damaged carrier relationships. Repeated misclassification flags your freight for inspection every time it moves.
Five ways to keep LTL class costs down
- Densify. Shrink packaging, cube out pallets — higher density means a lower class and rate.
- Measure honestly, every time. Overhang and pallet height count. Carriers use laser dimensioners; eyeballing loses.
- Document. Photograph packed freight with a tape measure visible, and keep scale weights.
- Ask about FAK agreements. Higher-volume shippers can negotiate Freight All Kinds pricing that caps class disputes entirely.
- Let your broker fight reclasses. A good partner audits carrier invoices and disputes bad reclasses with evidence — it's part of what you're paying for.
Where Qeep fits
Qeep Logistics quotes LTL freight across Canada and the U.S. with class verification before pickup — we confirm density, NMFC item and accessorials up front, so the invoice you approve is the invoice you pay. Got a shipment you're unsure how to class? Send us the dimensions and a specialist will class it for you, free.