Building materials/Density-rated
Lumber freight class and NMFC guide
Lumber is dense and stable, so density is rarely the hard part. The classification question is usually the species, grade, treatment, and whether the load ships as loose boards, a bundle, or a unit.
Reviewed November 11, 2026 · Reference 2026.11 · Estimate, not a classification
At a glance
DensityClassification basis
Density-rated
Typical packed density
25–40 lb/ft³
Tight estimate
Density-rated span
Class 55–65
Reclass risk
Low
Density and packaging are stable, and the handling unit is easy to measure the same way twice.
Handling flags
Density-based estimate. Confirm the NMFC item, the packaging form, and any density subprovision before booking.
What drives the class
The density story behind lumber.
Lumber density is driven by species and moisture content. Green lumber is heavier than kiln-dried lumber, and dense hardwoods are heavier than softwoods. The class usually stays in a narrow band because the material is solid and the bundle is easy to measure. The real risk is a mixed load: different species or treated and untreated lumber in one shipment may not share a single class. Keep the bundle descriptions specific.
Density-rated. Solid lumber is generally density-rated. Bundling and banding change the handling unit but not the underlying density story much.
Density thresholds
Where the estimate sits on the 2025 scale.
The highlighted rows are the classes touched by the endpoints of the typical density estimate. A single measured density returns one class; the span is a planning range. The scale is effective July 19, 2025.
| Density band | Class | Estimate |
|---|---|---|
| 50 or more lb/ft³ | 50 | Reference |
| 35 to under 50 lb/ft³ | 55 | Typical span |
| 30 to under 35 lb/ft³ | 60 | Typical span |
| 22.5 to under 30 lb/ft³ | 65 | Typical span |
| 15 to under 22.5 lb/ft³ | 70 | Reference |
| 12 to under 15 lb/ft³ | 85 | Reference |
| 10 to under 12 lb/ft³ | 92.5 | Reference |
| 8 to under 10 lb/ft³ | 100 | Reference |
| 6 to under 8 lb/ft³ | 125 | Reference |
| 4 to under 6 lb/ft³ | 175 | Reference |
| 2 to under 4 lb/ft³ | 250 | Reference |
| 1 to under 2 lb/ft³ | 300 | Reference |
| 0 to under 1 lb/ft³ | 400 | Reference |
Measure it right
The handling unit is the shipment.
Carriers measure what is tendered, not the product inside the box. Use the pallet, crate, or bundle as the handling unit and include everything that travels with it.
- Measure the bundle or unit, including banding and any protruding boards.
- Use gross weight; green lumber can be substantially heavier than the same volume of dried lumber.
- Measure each bundle separately if the lengths or species differ.
The formula
cube = L × W × H ÷ 1,728
density = gross lb ÷ cubeRound for display only. Compare the unrounded density to the scale boundary.
Heavy / concentrated load
Weight distribution, axle limits, and lift equipment need a pre-booking check.
Moisture-sensitive
Needs wrap, desiccant, or a dry loading position to avoid a damage claim.
Oversize / bulky
Long, tall, or irregular handling units can affect stowability and linear feet.
Pack it for the rating
Packaging changes the cube before it changes the class.
- Banding and dunnage are part of the handling unit. Keep the bundle square so it stacks predictably.
- Cover moisture-sensitive lumber or accept that rain can change the weight and the claim story.
Don't confuse it with
Adjacent items, different answers.
The most expensive classification mistake is usually a description that sounds close but is not the item. Check these before you copy a description from another shipment.
Plywood and panels
Treated lumber
Engineered wood
Before you book
Make the rating defensible.
- Confirm the item for species, grade, and treatment.
- Ask whether the carrier rates the bundle or the entire unit.
- Photograph the bundle ends and banding before pickup.
BOL description template
Starting pointLumber, [species], [dimensions], bundled, [quantity] bundles, [gross weight] lb gross, [length x width x height] in per bundle.
Add the confirmed NMFC item number before you tender the shipment. The template describes the freight; it is not a classification.
Common questions
Lumber and the 2025 scale.
How are lumber classified for LTL freight?
At an estimated packed density of 25–40 lb/ft³, the 2025 density scale spans Class 55–65. That is a planning span derived from the endpoints of the density estimate, not a promise that every shipment lands in every class. The NMFC item and the shipment as tendered control the final class.
What is the classification basis for lumber?
Density-rated. Solid lumber is generally density-rated. Bundling and banding change the handling unit but not the underlying density story much.
How do I confirm the NMFC item for lumber?
Confirm the item for species, grade, and treatment. Ask whether the carrier rates the bundle or the entire unit. Photograph the bundle ends and banding before pickup. Confirm the current item in ClassIT+ or with the carrier before booking.
Related commodities
Keep the comparison close.
Building materials
Plywood
Plywood is dense and ships in flat, stackable units. Density is stable, but the number of sheets per unit and the way the unit is banded can change the measured cube.
Class 55–60Building materials
Drywall
Drywall is heavy, brittle, and usually shipped in large flat units. Density is high and stable, so the class is rarely a surprise — but damage and handling are.
Class 50–55Building materials
Insulation
Insulation is extremely light for its cube, so it usually lands in the most expensive density tiers. Compression and packaging are the difference between a full load and a costly one.
Class 250–400Furniture & fixtures
Mattresses
Mattresses are bulky and light for their cube, so packed density usually lands in the low single digits. Compression, pallet height, and overhang move the result more than the mattress type.
Class 175–250Sources & limits
What this page is, and what it is not.
This is an independent planning reference, not the NMFC and not a carrier classification. The typical density is an estimate. The class span is derived from the 2025 density scale. The NMFC item, the carrier tariff, and the shipment as tendered control the final rating.
Reviewed November 11, 2026 · Reference 2026.11
- NMFTA — National Motor Freight Classification
The official classification system, its 18 classes, and the role of the NMFC item.
- NMFTA — 2025 NMFC changes
The July 19, 2025 effective date and the density-scale restructuring.
- NMFTA — ClassIT+
The licensed lookup for current NMFC item numbers and classification text.
- Estes — freight class and density calculator
Carrier measurement and density conventions used to sanity-check the ranges.
Next step
Measure the load, then check the class.
Use the freight class calculator for a measured density, the pallet calculator for the finished handling unit, and the chart for the full 2025 reference.