Paper & packaging/Density-rated
Corrugated box freight class and NMFC guide
Knocked-down corrugated boxes are light and bulky, and they nest into bundles that can be much denser than the cartons they become. Bundling is the density lever.
Reviewed November 11, 2026 · Reference 2026.11 · Estimate, not a classification
At a glance
DensityClassification basis
Density-rated
Typical packed density
4–8 lb/ft³
Planning estimate
Density-rated span
Class 100–175
Reclass risk
High
The commodity ships in several forms, is easy to under-measure, or changes cube sharply with assembly or packaging.
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 corrugated boxes (kd).
Knocked-down boxes are mostly air unless they are nested and banded. A loose bundle can be very light per cubic foot; a tight, banded unit is denser. The number of walls, the flute, and the print coverage also change the weight. The classification risk is high because the same SKU can ship as a small bundle, a full pallet, or a bale, and each form measures differently. State the bundle count and the dimensions on the BOL.
Density-rated. Knocked-down box stock is generally density-rated. Assembled boxes and printed retail cartons can carry different descriptions.
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 | Reference |
| 30 to under 35 lb/ft³ | 60 | Reference |
| 22.5 to under 30 lb/ft³ | 65 | Reference |
| 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 | Typical span |
| 6 to under 8 lb/ft³ | 125 | Typical span |
| 4 to under 6 lb/ft³ | 175 | Typical span |
| 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 pallet as banded, including any top board.
- Use gross weight with banding, wrap, and pallet.
- Measure loose bundles and full pallets separately; the density difference is large.
The formula
cube = L × W × H ÷ 1,728
density = gross lb ÷ cubeRound for display only. Compare the unrounded density to the scale boundary.
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.
- Keep bundles dry and banded; corrugated loses strength when wet.
- Do not over-compress printed boxes; the print and score lines can crack.
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.
Assembled boxes
Paperboard cartons
Paper towels and tissue
Before you book
Make the rating defensible.
- Confirm the item for knocked-down versus assembled boxes.
- Ask whether the carrier rates the bundle or the pallet.
- Photograph the bundle and banding before pickup.
BOL description template
Starting pointCorrugated boxes, knocked down, [quantity] bundles, [number] boxes per bundle, [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
Corrugated boxes (KD) and the 2025 scale.
How are corrugated boxes (kd) classified for LTL freight?
At an estimated packed density of 4–8 lb/ft³, the 2025 density scale spans Class 100–175. 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 corrugated boxes (kd)?
Density-rated. Knocked-down box stock is generally density-rated. Assembled boxes and printed retail cartons can carry different descriptions.
How do I confirm the NMFC item for corrugated boxes (kd)?
Confirm the item for knocked-down versus assembled boxes. Ask whether the carrier rates the bundle or the pallet. Photograph the bundle and banding before pickup. Confirm the current item in ClassIT+ or with the carrier before booking.
Related commodities
Keep the comparison close.
Paper & packaging
Paper towels & tissue
Paper towels and tissue are extremely light for their cube. The class is usually expensive, and compression, baling, and packaging are the only meaningful levers.
Class 175–300Paper & packaging
Printing paper
Printing paper is dense, heavy, and moisture-sensitive. The class is stable; the handling unit, skid height, and protection from water are the practical variables.
Class 50–55Plastics & chemicals
Foam products
Foam is one of the lightest freight commodities. Density depends almost entirely on compression and packaging, and the class can move several tiers with a tighter bundle.
Class 250–300Furniture & 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.
- FedEx Freight — freight class calculator
Carrier class and density reference 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.