Why does my density fall between two classes?

The NMFC density scale uses exact breakpoints. For example, 35.00 lbs/cu ft is class 55, but 34.99 lbs/cu ft is class 60. The difference of 0.01 lb can change the class. Carriers use the published density ranges with precision. If your calculated density is borderline, re-measure dimensions and weight carefully, and check the carrier's rounding rule. A small change in one dimension can move you to a lower class.

Can I use the legacy 18-class guideline for my shipment?

No. The NMFC has been updated as of July 19, 2025. Using the legacy guideline can lead to incorrect classification and a reclass charge. If a carrier or online tool uses the old scale, request that they apply the current 13-subprovision scale. The NMFTA publishes the current scale on nmfta.org.

What if my commodity doesn't have an NMFC item?

If no specific NMFC item exists for your commodity, use the density scale as the default. ClassIT+ from the NMFTA can help you search. If you cannot find an item, your freight class is determined solely by density. In this case, the density scale is the rule.

How do I calculate density for a pallet with overhang?

Measure the pallet's total dimensions including overhang. The handling unit is the pallet plus the freight on it. Do not measure the product alone. Multiply length, width, and height in inches, divide by 1728 to get cubic feet, then divide weight in pounds by that number. Overhang changes the volume, and therefore the density.

What is the difference between a reweigh and a reclass?

A reweigh is the act of weighing the shipment. A reclass is changing the class code based on the reweigh or an inspection. Carriers can reweigh under NMFC Item 360. After reweigh, if the density changes, they will reclass the shipment to the correct class. You can challenge a reclass if you have accurate documentation.

Does the NMFC density scale apply to all LTL shipments?

Yes, for interstate LTL shipments within the United States. The NMFC is the governing standard. Canada has its own classification system (NMFCC), which is similar but not identical. Mexico does not use the NMFC. For cross-border shipments, check with the carrier for the applicable classification.

Why do some carriers use a different class than the density scale suggests?

The NMFC assigns class per commodity item. If your commodity has a specific NMFC item, the class from that item overrides the density scale. For example, a high-liability item like electronics may have a higher class than its density alone would dictate. Always look up the NMFC item for your commodity before using the density scale.

Freight Class Chart: NMFC Density Scale and Classes

Freight Class Chart: The Only NMFC Density Scale You Need

Most shipping guides still show the old 18-class density guideline as the NMFC standard. That is wrong. The NMFTA replaced it on July 19, 2025, with a 13-subprovision scale under Docket 2025-1. This freight class chart is the one current scale. Use it to look up which class a given density falls in, and ignore any table that still lists 18 classes as NMFC rule.

The NMFC density scale maps pounds per cubic foot to a class between 50 and 500. Higher density means a lower class and a lower rate per CWT. The scale has 13 subprovisions, each with a specific density range. Below is the exact mapping from the NMFTA Docket 2025-1 final decision, published on nmfta.org.

Current NMFC Density Scale (13 Subprovisions, effective July 19, 2025):

Class 50: Density 50+ lbs/cu ft
Class 55: Density 35-49.99 lbs/cu ft
Class 60: Density 30-34.99 lbs/cu ft
Class 65: Density 22.5-29.99 lbs/cu ft
Class 70: Density 15-22.49 lbs/cu ft
Class 85: Density 12-14.99 lbs/cu ft
Class 92.5: Density 10.5-11.99 lbs/cu ft
Class 100: Density 9-10.49 lbs/cu ft
Class 110: Density 8-8.99 lbs/cu ft
Class 125: Density 7-7.99 lbs/cu ft
Class 150: Density 6-6.99 lbs/cu ft
Class 175: Density 5-5.99 lbs/cu ft
Class 200: Density 4-4.99 lbs/cu ft
Class 250: Density 3-3.99 lbs/cu ft
Class 300: Density 2-2.99 lbs/cu ft
Class 400: Density 1-1.99 lbs/cu ft
Class 500: Density less than 1 lb/cu ft

The Legacy 18-Class Density Guideline and Where It Still Appears

Before July 2025, the NMFC had an 18-class density guideline. It used the same class numbers (50 to 500) but with different breakpoints. For example, the old scale had a class 77.5 for densities 13.5-15 lbs/cu ft, and a class 92.5 for 10.5-12 lbs/cu ft, but the current scale eliminated class 77.5 entirely and shifted the 92.5 breakpoint. Many online calculators and printed reference charts still show the legacy 18-class table. If your source lists 18 classes, it is not the current NMFC rule.

Legacy NMFC 18-Class Density Guideline (superseded July 19, 2025):

Class 50: 50+ lbs/cu ft
Class 55: 35-50 lbs/cu ft
Class 60: 30-35 lbs/cu ft
Class 65: 22.5-30 lbs/cu ft
Class 70: 15-22.5 lbs/cu ft
Class 77.5: 13.5-15 lbs/cu ft
Class 85: 12-13.5 lbs/cu ft
Class 92.5: 10.5-12 lbs/cu ft
Class 100: 9-10.5 lbs/cu ft
Class 110: 8-9 lbs/cu ft
Class 125: 7-8 lbs/cu ft
Class 150: 6-7 lbs/cu ft
Class 175: 5-6 lbs/cu ft
Class 200: 4-5 lbs/cu ft
Class 250: 3-4 lbs/cu ft
Class 300: 2-3 lbs/cu ft
Class 400: 1-2 lbs/cu ft
Class 500: less than 1 lb/cu ft

If a carrier or 3PL uses the old scale, your class may come out wrong. The difference is most noticeable for densities around 12-15 lbs/cu ft, which could be class 77.5 (legacy) or class 85 (current). Check the date on any density chart you use. If it does not say "13 subprovisions" or cite Docket 2025-1, it is legacy.

Example Commodities by Class With NMFC Item Sources

The NMFC assigns a class to each commodity through a numbered item. Density is the primary factor, but stowability, handling, and liability can override it for specific items. You must cite the NMFC item to assign a class; you cannot rely on density alone. Below are instances with their NMFC item numbers from the NMFC item text. These are not a substitute for looking up your own commodity.

High-Density Freight: Class 50 to 70

Class 50, Steel Beams (NMFC Item 133300): Densities above 50 lbs/cu ft. Typical examples: steel ingots, concrete blocks, bricks.

Class 60, Car Parts (NMFC Item 16900): Density 30-34.99 lbs/cu ft. Typical examples: heavy machinery castings, stacked lumber.

Class 70, Automobile Engines (NMFC Item 110000): Density 15-22.49 lbs/cu ft. Typical examples: metal castings, bottled beverages.

Mid-Range Freight: Class 92.5 to 175

Class 92.5, Computers (NMFC Item 117930): Density 10.5-11.99 lbs/cu ft. Typical examples: monitors, small electronics.

Class 125, Small Household Goods (NMFC Item 77760): Density 7-7.99 lbs/cu ft. Typical examples: drywall, furniture parts.

Class 175, Clothing (NMFC Item 200520): Density 5-5.99 lbs/cu ft. Typical examples: sofas, upholstered furniture.

Low-Density Freight: Class 250 to 500

Class 250, Fiberglass Insulation (NMFC Item 81540): Density 3-3.99 lbs/cu ft. Typical examples: pillows, foam products.

Class 500, Empty Plastic Bottles (NMFC Item 166300): Density less than 1 lb/cu ft. Typical examples: large empty crates, foam peanuts.

To find your NMFC item, use the NMFTA's ClassIT+ tool. If no specific item exists for your commodity, use the density scale above as the default guide.

Reading the Chart for Your Shipment

To use this freight class chart, you need the density of your handling unit. A handling unit is the individual piece of freight you tender, a pallet, a box, a drum. Density is weight in pounds divided by volume in cubic feet. Measure length, width, and height in inches. Multiply them, divide by 1728 to get cubic feet. Then divide the weight by that number.

Dimension Rounding Changes the Class

Carriers round dimensions per their rules tariff. Many round up to the next inch. Some round to the nearest inch. This can shift your calculated density by 5-15%. For example, a box that measures 48.2 x 40.1 x 36.5 inches may be rounded up to 49 x 41 x 37 inches, increasing volume and lowering density. Check the carrier's rules tariff for rounding rules before you calculate.

What to Do If Your Class Seems Too High

Re-measure dimensions including pallet overhang. Overhang is part of the handling unit.
Weigh the shipment on a calibrated scale. A difference of 5 lbs on a light pallet can change the class.
Reduce packaging. Cut bubble wrap, remove empty space, or use a smaller pallet.
Look up the NMFC item. Some commodities have a fixed class regardless of density.

Challenge a Reclass Properly

Carriers have the right to reweigh and inspect under NMFC Item 360. If they reclass your shipment, ask for the reweigh certificate and the NMFC item they used. Verify the density calculation with their rounding rule. If you disagree, provide your own measurements and the NMFC item. Most carriers will adjust if you have documentation.

For a full cost estimate, remember that LTL pricing includes the CWT rate from the base tariff (published by SMC3 CzarLite), plus accessorial charges for liftgate, residential delivery, or inside delivery. The class determines the CWT rate, but the final charge is the sum of all components.

Freight Class Density Chart: A Printable Reference

Print this section for a quick reference. Write your handling unit's density and class in the margin. This is the freight class density chart you need on the warehouse wall.

Current NMFC Density Scale (13 Subprovisions):

Class 50: 50+
Class 55: 35-49.99
Class 60: 30-34.99
Class 65: 22.5-29.99
Class 70: 15-22.49
Class 85: 12-14.99
Class 92.5: 10.5-11.99
Class 100: 9-10.49
Class 110: 8-8.99
Class 125: 7-7.99
Class 150: 6-6.99
Class 175: 5-5.99
Class 200: 4-4.99
Class 250: 3-3.99
Class 300: 2-2.99
Class 400: 1-1.99
Class 500: less than 1

Density in lbs/cu ft. Source: NMFTA Docket 2025-1 final decision, effective July 19, 2025.

Legacy 18-Class Guideline (superseded):

Class 50: 50+
Class 55: 35-50
Class 60: 30-35
Class 65: 22.5-30
Class 70: 15-22.5
Class 77.5: 13.5-15
Class 85: 12-13.5
Class 92.5: 10.5-12
Class 100: 9-10.5
Class 110: 8-9
Class 125: 7-8
Class 150: 6-7
Class 175: 5-6
Class 200: 4-5
Class 250: 3-4
Class 300: 2-3
Class 400: 1-2
Class 500: less than 1

Density in lbs/cu ft. Do not use this for current classification.