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 freight class 55?
Freight class 55 is one of the 18 classes in the National Motor Freight Classification (NMFC). It applies to LTL shipments whose density falls between 35 to under 50 lb/ft³. Density is weight ÷ volume, so a shipment lands in class 55 when it weighs that much for the space it occupies. Lower classes (denser freight) cost less to ship; higher classes (lighter, bulkier freight) cost more, because they use more trailer space per pound.
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
Density is weight ÷ volume (cubic feet = L × W × H in inches ÷ 1,728). Here is how real shipments land in — and fall out of — class 55:
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.
Typical class 55 commodities
Goods that are commonly rated freight class 55 include:
- Hardwood flooring
- Bricks and mortar
- Cement and concrete
- Moulding and trim
- Ceramic tile
These are typical examples. The exact class of any item depends on its NMFC item number and measured density — always confirm with your carrier or broker.
Commodity guides that overlap class 55:
Check if your shipment is class 55
Enter your dimensions and weight — if the density lands in 35 to under 50 lb/ft³, you’re in 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
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Estimates only — verify freight class/NMFC and chargeable weight with your carrier.
How freight class is calculated (density scale)
Freight class is set by density = weight (lb) ÷ volume (ft³). Higher density → lower class → typically lower cost. Volume here is L × W × H × quantity.
| Density (lb/ft³) | Class |
|---|---|
| 50+ | 50 |
| 35 – 50 | 55 |
| 30 – 35 | 60 |
| 22.5 – 30 | 65 |
| 15 – 22.5 | 70 |
| 13.5 – 15 | 77.5 |
| 12 – 13.5 | 85 |
| 10.5 – 12 | 92.5 |
| 9 – 10.5 | 100 |
| 8 – 9 | 110 |
| 7 – 8 | 125 |
| 6 – 7 | 150 |
| 5 – 6 | 175 |
| 4 – 5 | 200 |
| 3 – 4 | 250 |
| 2 – 3 | 300 |
| 1 – 2 | 400 |
| 0 – 1 | 500 |
Frequently asked questions
What is freight class 55?
Freight class 55 is the NMFC class for shipments with a density of 35 to under 50 lb/ft³. Typical examples include hardwood flooring, bricks and mortar, cement and concrete.
What products are freight class 55?
Goods commonly rated class 55 include hardwood flooring, bricks and mortar, cement and concrete, moulding and trim, ceramic tile. The actual class depends on the item's density and NMFC item number, so verify with your carrier.
How is freight class 55 determined?
Divide the shipment weight in pounds by its volume in cubic feet. A density of 35 to under 50 lb/ft³ maps to class 55 on the NMFC density scale. Use the calculator above to check your shipment.
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.