Item 222 and Freight Classification: How Corrugated Box Specifications Affect Shipping Costs

If you ship corrugated boxes via LTL (less-than-truckload) freight, the National Motor Freight Classification (NMFC) system directly affects your shipping costs -- and the specifications of your corrugated packaging play a surprisingly large role in determining what you pay. Item 222, the NMFC classification for corrugated boxes and packaging, is one of the most commonly referenced items in the freight classification system, and understanding how it works can save significant money on your logistics spend.

This guide explains the NMFC classification system, how Item 222 applies to corrugated packaging, and how your box specifications influence freight class and cost.

What Is the NMFC System?

The National Motor Freight Classification is a standardized system that categorizes commodities shipped via LTL freight into classes, which carriers use to set pricing. Managed by the National Motor Freight Traffic Association (NMFTA), the system assigns every commodity a class from 50 to 500, with 50 being the cheapest to ship and 500 the most expensive.

How Freight Class Is Determined

Freight class is based on four characteristics:

1. Density -- Weight per cubic foot. Denser shipments are cheaper to ship (lower class).
2. Stowability -- How easily the freight can be loaded and stored in a trailer.
3. Handling -- How much labor and care is needed to move the freight.
4. Liability -- The risk of damage or theft.

For corrugated boxes and most manufactured goods, density is the dominant factor. Higher density equals a lower freight class, which equals a lower shipping cost per pound.

The Freight Class Scale

The difference between Class 70 and Class 125 is roughly double the freight cost per hundredweight (CWT). For a company shipping 20 pallets per week, dropping even one freight class can save thousands of dollars per month.

Item 222: Corrugated Boxes in the NMFC

NMFC Item 222 covers "boxes, corrugated or solid fibre" -- the classification for shipments of corrugated boxes themselves (empty boxes, not the products inside them). This applies to:

• Corrugated box manufacturers shipping finished boxes to customers
• Companies shipping empty boxes between facilities
• Packaging distributors delivering box inventory

Why Item 222 Matters

Empty corrugated boxes are inherently low-density. A pallet of flat (knocked-down) RSCs might weigh 300-500 lbs but occupy 80+ cubic feet of trailer space. That density -- roughly 4-6 lbs per cubic foot -- puts empty corrugated boxes in Class 150-200, one of the most expensive freight classifications.

This is why freight costs can represent 15-25% of the total delivered cost of corrugated boxes, and why the way boxes are configured for shipping has such a large impact on total cost.

Density Calculation for Corrugated Box Shipments

Density = Total shipment weight (lbs) / Total shipment volume (cubic feet)

Where volume is calculated as: (Length x Width x Height of each pallet, in inches) / 1,728

Example:

• Pallet of knocked-down RSCs: 48" x 40" x 48" = 53.3 cubic feet
• Pallet weight: 350 lbs
• Density: 350 / 53.3 = 6.6 lbs/cubic foot = Class 150

Now compare that to the same boxes bundled more tightly:

• Pallet of knocked-down RSCs: 48" x 40" x 36" = 40 cubic feet
• Pallet weight: 350 lbs (same boxes, just packed tighter)
• Density: 350 / 40 = 8.75 lbs/cubic foot = Class 110

By reducing the pallet height from 48" to 36" (tighter bundling), the freight class dropped from 150 to 110 -- a potential cost reduction of 20-25% on that pallet's freight charges.

How Box Specifications Affect Freight Class

Box Size and Style

Larger boxes occupy more cubic volume per unit when knocked down, reducing pallet density. The relationship is straightforward:

• Smaller boxes = more boxes per pallet = higher pallet weight = higher density = lower freight class
• Larger boxes = fewer boxes per pallet = lower pallet weight = lower density = higher freight class

Box style also matters:

Board Grade and Weight

Heavier board grades (44 ECT, double wall) produce boxes that weigh more per unit. While heavier boxes increase the raw material cost, they also increase pallet weight -- which can actually improve freight density and reduce the freight cost per box.

This creates a counterintuitive dynamic: in some cases, using a heavier board grade results in a lower total delivered cost because the freight savings from a lower classification outweigh the material cost increase.

Example:

• 1,000 RSCs in 32 ECT: 300 lbs per pallet, 40 cubic feet, density = 7.5 = Class 125
• 1,000 RSCs in 44 ECT: 420 lbs per pallet, 40 cubic feet, density = 10.5 = Class 100

The Class 100 shipment might save $2-$4 per CWT in freight rates, which on a 420-lb pallet translates to $8.40-$16.80 in freight savings -- potentially more than the $5-$10 additional material cost for the heavier board.

This math doesn't always work out, but it's worth evaluating when freight is a significant cost component.

Flute Type

Flute type affects the knocked-down thickness of boxes, which directly impacts pallet height and density:

Switching from C-flute to B-flute for the same box size reduces the knocked-down thickness by approximately 33%, allowing more boxes per pallet and improving density.

Strategies to Optimize Freight Classification

1. Maximize Pallet Density

Work with your corrugated supplier to optimize how boxes are bundled and palletized:

• Tighter bundling -- Compress bundles to minimize air space between boxes
• Optimized bundle orientation -- Orient box blanks to maximize pallet footprint utilization
• Appropriate pallet height -- Sometimes a shorter, denser pallet at a lower freight class costs less to ship than a taller pallet at a higher class
• Consistent bundle sizes -- Uniform bundles stack more efficiently than mixed sizes

2. Combine Shipments

Mixing heavy items with light items (like corrugated boxes) on the same pallet can improve overall shipment density. If you're receiving corrugated boxes and other packaging materials from the same supplier or distribution point, combining them on a single shipment can shift the overall density to a lower freight class.

3. Negotiate Commodity-Based Pricing

Rather than accepting class-based LTL rates, negotiate commodity-based pricing with your carrier. Many LTL carriers will offer a flat rate per pallet or per CWT for corrugated box shipments, bypassing the classification system entirely. This is especially effective for regular, predictable shipments.

4. Consider Full Truckload

If your order volume supports it, full truckload (FTL) shipping eliminates the freight class issue entirely. FTL is priced per mile per truck, regardless of commodity density. The breakpoint where FTL becomes cheaper than LTL varies by lane but is often around 8-12 pallets.

5. Use Supplier Delivery

Many corrugated manufacturers include delivery in their box pricing (FOB destination). In this case, the manufacturer manages the freight, and the classification impact is built into their delivered price. Compare FOB destination pricing from multiple suppliers to ensure the freight component is competitive.

6. Regional Sourcing

Shipping corrugated boxes shorter distances is always more cost-effective. The impact of freight classification is amplified on longer lanes. Sourcing from a supplier 100 miles away versus 500 miles away can reduce freight costs by 50-70% regardless of classification.

See our guide on evaluating corrugated box suppliers for more on the importance of supplier location.

Understanding Your Bill of Lading (BOL)

When shipping corrugated boxes via LTL, the Bill of Lading must accurately describe the commodity and include the correct NMFC item number and class. Errors on the BOL can result in:

Re-Classification

Carriers have the right to inspect and re-weigh/re-measure shipments. If the actual density doesn't match the declared class, the carrier will reclassify the shipment -- usually to a higher (more expensive) class -- and bill accordingly.

Re-classification is common for corrugated box shipments because:

• Shippers sometimes declare a lower class than the actual density supports
• Pallet dimensions change if boxes shift during transit
• Carriers are increasingly using automated measurement systems at terminals

Avoiding Re-Class Fees

• Calculate density accurately before declaring class
• Measure actual pallet dimensions (not the box dimensions -- the actual footprint and height of the palletized load)
• Weigh pallets on a calibrated scale
• Document the measurement with photos if possible
• Use stretch wrap to maintain pallet integrity during transit

Item 222 vs. Product Freight Class

An important distinction: Item 222 covers the corrugated boxes themselves as a commodity. When you're shipping products inside corrugated boxes, the freight classification is based on the product, not the box.

However, the box specifications still matter because they affect the overall shipment density:

Example: Shipping canned goods

• Product (canned goods) classified under NMFC Item 73000, Class 70
• Product weight: 30 lbs per case
• Box A: 12 x 12 x 12" (1 cubic foot), giving density of 30 lbs/cu ft, resulting in Class 60-65
• Box B: 16 x 14 x 14" (1.81 cubic feet), giving density of 16.6 lbs/cu ft, resulting in Class 70-77.5

The oversized Box B pushes the density lower, potentially increasing the freight class by one or two tiers. This is another argument for right-sizing your corrugated boxes -- it reduces not only material and DIM weight costs but potentially LTL freight costs as well.

Working With Your Corrugated Supplier on Freight Optimization

Your corrugated box supplier ships corrugated all day, every day. They understand freight classification intimately and can help you optimize:

• Pallet configuration recommendations -- How to maximize density for your specific box sizes
• Bundle count optimization -- The right number of boxes per bundle for density and handling
• Alternative specifications -- Whether a different flute or board grade could improve freight economics
• Consolidation opportunities -- Combining multiple box sizes on a single shipment
• Delivery options -- FOB destination pricing that may be more competitive than managing your own freight

These conversations are worth having during the quoting process -- see our guide on getting quotes from corrugated manufacturers.

The Bottom Line

Freight classification under the NMFC system is a significant but often overlooked cost factor in corrugated packaging procurement. The specifications of your corrugated boxes -- size, board grade, flute type, and pallet configuration -- directly influence freight density and classification, which in turn affects what you pay to ship.

The most impactful strategies are maximizing pallet density through optimized bundling and orientation, negotiating commodity-based carrier rates, sourcing regionally to minimize freight distance, and right-sizing boxes to improve product shipment density.

For any company where corrugated freight represents more than 10% of the total delivered packaging cost, a systematic freight optimization effort -- in partnership with your corrugated supplier and freight carrier -- can yield 10-25% savings.

For current corrugated market pricing context, visit our pricing tracker.