Freight Class 55
Class 55 covers very dense building and construction materials. These goods are heavy for their size (35–50 lb/ft³) and stack well, keeping rates low.
What is class 55 freight?
Class 55 is for heavy building materials and similar dense freight: hardwood flooring, ceramic tile, bricks, cement. It covers 35 to just under 50 pounds per cubic foot, a wide band, so full pallets of these goods usually stay in it. On a 48 × 40 × 48 in pallet (53.3 ft³), class 55 means about 1,867 to 2,667 lb, so heavy pallets like these are often built lower than 48 in. At 50 lb/ft³ it becomes class 50; under 35, class 60.
Class 55 freight description
Class 55 is the second-cheapest class on the NMFC scale, describing freight that weighs 35 to just under 50 pounds per cubic foot. This is jobsite-and-warehouse territory: bundled hardwood flooring, palletized tile, bagged cement, boxed mouldings — goods that are nearly solid material with very little packaging air. They stack flat, survive handling, and let the carrier use a trailer's full weight capacity, which is exactly what the low rate rewards.
The step below, class 50, demands 50 lb/ft³ or more and is effectively reserved for the very densest loads — steel stock, fasteners, brick. Most dense building material never gets there once it's on a pallet, because the pallet itself and the gaps between bundles dilute the density. That's why so much construction freight books at class 55 rather than 50: the material qualifies, the packaging doesn't.
Class 55 worked examples
Three pallets measured at their outside size. The last one shows how a partial top layer moves the class.
Palletized hardwood flooring — class 55
Bundles of hardwood flooring on a 48" × 40" pallet, stacked 36" high, 1,600 lb.
48 × 40 × 36 = 69,120 in³ ÷ 1,728 = 40.0 ft³. Density = 1,600 lb ÷ 40.0 ft³.
40.0 lb/ft³ → inside 35–50 → class 55.
Ceramic tile, low and tight — class 55
Boxed ceramic tile on a 48" × 40" pallet, only 24" high, 1,200 lb.
48 × 40 × 24 = 46,080 in³ ÷ 1,728 = 26.7 ft³. Density = 1,200 lb ÷ 26.7 ft³.
45.0 lb/ft³ → class 55, with headroom.
The same flooring pallet, 250 lb lighter — class 60
The identical 40 ft³ flooring pallet, loaded to 1,350 lb.
Density = 1,350 lb ÷ 40.0 ft³ = 33.75 lb/ft³ — under the 35 lb/ft³ floor.
33.75 lb/ft³ → class 60. A partial top layer was the difference.
Shipping at class 55: what to watch
Weight, not space, is the constraint for class-55 freight. A single 48" × 40" pallet in this band routinely carries 1,400–2,000 pounds, so axle-weight limits and pallet ratings matter more than trailer cube. Use pallets rated for the load, keep the footprint tight, and band or shrink-wrap so the stack ships as one solid unit — a collapsed stack of tile is a claim, and loose bundles measured separately can rate worse.
Mind the 35 lb/ft³ floor. Add a light top layer — say cartons of trim or underlayment on top of the flooring — and the blended density of the pallet can slip under 35, rebilling the whole unit at class 60 or higher. When you mix dense and light goods, it often prices better to keep the dense freight on its own pallet and let the light freight take its own class, rather than blending both onto one unit. Run each configuration through the calculator below and compare.
What ships as class 55
Dense goods that often measure into class 55. A specific NMFC listing can still set a different class:
- Hardwood flooring
- Bricks and mortar
- Cement and concrete
- Moulding and trim
- Ceramic tile
Related commodity guides:
Is your shipment class 55?
Enter the pallet size and its full weight. A result from 35 to just under 50 lb/ft³ is class 55.
Density-based estimate. Some commodities carry a fixed NMFC class — check our freight class by commodity pages.
Estimated Freight Class
Density
42.51
lb/ft³
Volume
53.33
ft³
Weight
2,267
lb
35–50 lb/ft³ → Class 55
NMFC density scale (Docket 2025-1, effective July 19, 2025)
Free PDF includes a watermark. Pro removes it & adds your brand.
Estimates only — verify freight class/NMFC and chargeable weight with your carrier.
Uses the 13-tier NMFC density scale (Docket 2025-1). See the full freight class chart.
Frequently asked questions
What goods are class 55?
Hardwood flooring, ceramic tile, bricks and bagged cement often measure 35 to 50 lb/ft³. In the examples above, a pallet of hardwood flooring measured 40.0 lb/ft³ and ceramic tile 45.0 lb/ft³.
Is freight class 55 cheap to ship?
Yes — it's the second-lowest of the 18 NMFC classes, so per hundred pounds it rates below everything except class 50. Dense freight uses the trailer's weight capacity instead of its space, and tariffs price that favorably.
What's the difference between freight class 50 and 55?
Density. Class 50 requires 50 lb/ft³ or more; class 55 covers 35 to just under 50. Palletized building materials usually land at 55 because the pallet and bundle gaps pull the measured density below the class-50 line even when the raw material is denser.
What density do I need for freight class 55?
35 to just under 50 pounds per cubic foot, measured on the whole handling unit — pallet included. Divide total weight by total cubic feet (L × W × H in inches ÷ 1,728) and check the result against the band.