Freight Class for Lumber
Lumber is dense and solid, so under the 2025 density-based scale banded lumber sits at the low, inexpensive end — roughly class 60 to 70. Moisture content and how tightly it is bundled move the number. Here’s the typical range, the math, and the exact class one click away.
The short answer
Typical packaged lumber runs about 15–30 PCF, which maps to roughly class 60–70 on the 2025 NMFTA scale. Worked example — a banded unit of framing lumber, 96×42×24 in at 1100 lb:
96×42×24 ÷ 1,728 = 56 ft³ → 1100 ÷ 56 = 19.64 PCF → Class 70
Why lumber classes the way it does
Dimensional lumber is one of the denser commodities that ships LTL: a banded unit is mostly solid wood with little wasted space. On the 2025 NMFTA scale, which rates on density (pounds per cubic foot), that high density lands lumber near the bottom of the class scale where rates are lowest.
The band shifts with species and moisture. Heavier, greener, or hardwood units pack more pounds per cubic foot and can reach class 55–60. Lighter, kiln-dried softwood is a bit less dense and sits around class 70. Loosely stacked or short bundles with air gaps class higher — so band the unit tightly and calculate from its real weight and dimensions.
How to calculate it for your shipment
Multiply your packed length, width, and height in inches, divide by 1,728 to get cubic feet, then divide the weight by that volume for density in pounds per cubic foot (PCF). Map the PCF to the class on the NMFTA scale. The Freight Density Calculator does it in one step; the Target Class Calculator runs it backward to find the weight that would hit a class you’re aiming for. Prefer a lookup? The density-to-freight-class chart lists every class and its PCF band.
Get the class right the first time
Because the 2025 scale rates on density, sloppy dimensions are what get lumber reclassed and back-billed. Measure to the farthest points on the packed piece, weigh it on a certified scale, and calculate the density before pickup — don’t eyeball the class. For the full picture of how density-based classification works, start with the freight class guide, and see why freight gets reclassed if a carrier disputes your number. Freight class is set by the NMFTA; look up your specific NMFC item with the NMFTA.
Frequently asked
What is the freight class for lumber?
Banded dimensional lumber typically falls between class 60 and class 70 under the 2025 density-based scale because it is dense and solid. A banded unit of framing lumber at about 19.6 PCF classes at 70, for example. Greener or hardwood units are denser and can class lower. Calculate the exact class from the unit’s weight and dimensions.
Does moisture content change the freight class of lumber?
Yes. Green or wet lumber weighs more per cubic foot than kiln-dried, so it is denser and can class lower. As lumber dries it loses weight without losing much volume, which lowers density and can nudge the class up. Weigh the actual unit you are shipping.
Why is lumber cheaper to ship than furniture made from it?
Density. A banded unit of lumber is nearly solid wood, so it is dense and classes low. Finished furniture made from the same wood is full of air and open space, so it is light for its size and classes much higher under the density-based scale.
How do I calculate freight class for lumber?
Multiply the unit length, width, and height in inches and divide by 1,728 for cubic feet. Divide the weight in pounds by that volume to get density in pounds per cubic foot (PCF), then map the PCF to a class on the NMFTA scale. The Freight Density Calculator does it in one step.