What is Freight Class 50? Density, Examples & Cost

Freight class 50 corresponds to a density of 50 or more pounds per cubic foot. Density is weight divided by volume, so a 2,200 lb shipment occupying 40 cubic feet has a density of 55.0 lbs/ft³ - class 50. Compute your shipment's density with the Freight Class Calculator.

Class 50 is the lowest and cheapest class, reserved for extremely dense, durable freight that packs maximum weight into minimal space. Commodities that commonly rate at this class include:

• Bricks, sand, and gravel
• Nuts, bolts, and fasteners in bulk
• Steel rod and bar stock
• Dense machined metal parts

These are typical examples - the binding class is always the commodity's actual NMFC provision, which you can confirm with the NMFC Lookup.

LTL carriers sell trailer space, so density drives price. Class 50 is cheaper than class 55 and among the priciest classes. Because it sits on the dense end of the scale, class 50 earns the carrier good revenue per cubic foot, so the rate per hundredweight (CWT) is relatively low.

If your shipment is borderline between class 55, packaging changes that adjust density can move it into an adjacent class and change the bill. A 2,200 lb shipment in 40 ft³ rates class 50 (55.0 lbs/ft³); spreading the same weight over more space lowers the density and bumps it toward class 55. Always confirm before quoting with the NMFC Lookup or the NMFC API.

Class 50's position on the freight class ladder, with its immediate neighbors:

• Class 50 (50+ lbs/ft³) - the lowest and cheapest class, reserved for extremely dense, durable freight that packs maximum weight into minimal space.
• Class 55 (35-50 lbs/ft³) - lighter than class 50, so it rates a step more expensive. Typical freight: hardwood flooring.

Because adjacent classes are separated by narrow density bands, an inch of extra packaging or a lighter-than-expected load can shift a shipment between them - so accurate measurement matters most near these boundaries. See Freight Class Explained for the complete 18-class ladder.

You can estimate class 50 yourself in three steps before you ever request a quote:

1. Measure the packaged shipment - length, width, and height in inches, including the pallet, crating, and any overhang.
2. Convert to cubic feet and divide: volume = (L × W × H) ÷ 1,728, then density = weight ÷ volume.
3. Match the density to the chart. A result of 50 or more pounds per cubic foot lands in class 50.

Because this class sits at the open end of the scale, almost any further change in bulk keeps it at class 50. The Freight Class Calculator runs this calculation automatically, and the NMFC API returns the authoritative class for a known commodity so your TMS never has to guess.

Most class 50 billing adjustments come from two avoidable mistakes:

• Measuring the product, not the packaged unit. Class is based on the shipment as tendered - pallet, crating, and overhang included. Measuring only the product understates volume and overstates density.
• Assuming density alone. Some commodities carry a fixed NMFC class regardless of density. Verify the item's actual provision instead of trusting the density estimate.

When a carrier inspects a shipment and finds the class understated, they reclassify it and rebill the difference, frequently adding an adjustment fee. For freight near class 50, the safest workflow is to measure precisely, calculate density, and then confirm the commodity's actual NMFC provision rather than trusting a single estimate. if it comes back just below, expect the pricier class 55.

The procedure in How to Determine Freight Class walks through measuring, calculating density, and confirming the class so a carrier inspection doesn't surprise you. To classify at scale, the NMFC API returns the class and NMFC item number for any commodity in a single call - the same data, automated for your quoting or TMS pipeline.