Calculate your NMFC freight class by density, dimensions, and weight. Get the correct LTL freight class for accurate shipping quotes — instantly.
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Calculate your NMFC freight class by density, dimensions, and weight. Get the correct LTL freight class for accurate shipping quotes — instantly.
NMFC Freight Class
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⚠️ Disclaimer: This calculator provides density-based freight class estimates. Some commodities have fixed NMFC class assignments that override density. Always verify with your carrier or the NMFC directory for regulated commodities.
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Sources & Methodology
✓Formulas and reference data verified against authoritative sources listed below.
Practical guide to LTL freight classes and density-based classification
Methodology: Freight class = density-based NMFC category. Volume = (L × W × H) ÷ 1728 cubic feet. Density = Weight ÷ Volume. Class matched per NMFC density table from Class 500 (lightest) to Class 50 (densest).
⏱ Last reviewed: April 2026
How to Calculate Freight Class
Freight class is the NMFC standardized category used by LTL (less-than-truckload) carriers to price shipments. There are 18 freight classes ranging from Class 50 (densest, cheapest to ship) to Class 500 (lightest and bulkiest, most expensive). The primary classification factor is density — weight per cubic foot of the shipment.
Step-by-Step Freight Class Calculation
Measure the length, width, and height of your shipment in inches. Multiply all three dimensions to get cubic inches, then divide by 1,728 to convert to cubic feet. Divide the total weight in pounds by the cubic footage to get density in lbs/cu ft. Match that density to the NMFC class table.
The 18 NMFC Freight Classes
Classes range from 50 to 500. Class 50 covers the densest freight (50+ lbs/cu ft) — heavy items like flooring, bricks, or steel. Class 500 is for extremely light freight under 1 lb/cu ft — assembled furniture or ping pong balls. The classes in between cover the full range of commercial freight.
Why Accurate Freight Class Matters
Incorrect freight classification leads to reclassification fees charged by carriers at the dock. If your stated class is lower than what the carrier measures, you pay the difference plus a reclassification surcharge. Accurate upfront calculation prevents unexpected post-delivery invoices.
Commodity-Based vs. Density-Based Classification
Most freight is classified by density. However, certain commodities — such as electronics, hazardous materials, and some vehicles — have fixed NMFC class assignments regardless of density. Always check the NMFC directory if your product has a specific commodity code that may override density-based classification.
Density (lbs/cu ft) = Weight ÷ (L × W × H ÷ 1728)
Volume in cubic feet = L × W × H ÷ 1728. Density = Weight ÷ Volume. Match density to NMFC class table: Class 50 (≥50 pcf) through Class 500 (<1 pcf).
NMFC Density Formula
Density (lbs/cu ft)
Freight Class
Typical Examples
≥ 50
Class 50
Flooring, bricks, steel, cast iron
35 – 50
Class 55
Hardwood floors, construction materials
22.5 – 30
Class 65
Auto parts, boxed books, car accessories
13.5 – 15
Class 77.5
Tires, bathroom fixtures
9 – 10.5
Class 100
Wine cases, caskets, boat covers
6 – 7
Class 150
Auto engines, machinery parts
3 – 4
Class 250
Bamboo furniture, mattresses
< 1
Class 500
Ping pong balls, assembled furniture
💡 Pro Tip: Always measure the total dimensions of the shipment including pallet overhang and any protruding components. LTL carriers measure at the dock and can reclassify shipments — adding fees after delivery. Accurate upfront measurements prevent surprise invoices.
Frequently Asked Questions
Freight class is a standardized NMFC category assigned to LTL shipments that determines the base shipping rate. The 18 classes range from Class 50 (dense, cheap to ship) to Class 500 (light and bulky, expensive). Carriers use class along with origin, destination, and weight to calculate your freight bill.
The primary method is density: Density = Weight ÷ (L × W × H ÷ 1728). Then match the density to the NMFC class table. A 200 lb shipment measuring 48×40×36 inches has a volume of 4 cu ft and density of 50 lbs/cu ft, putting it at Class 50.
Class 50 is the lowest freight class for the densest shipments (≥50 lbs/cu ft) and typically commands the lowest rates per pound. Class 500 is the highest class for the lightest freight (<1 lb/cu ft) and commands the highest rates per pound.
Yes. Total weight includes the pallet. Standard wood pallets weigh 35–50 lbs. Always add pallet weight to your freight weight before calculating density and class.
If your stated freight class does not match the actual density when the shipment arrives at the carrier dock, they reclassify it and charge the difference plus a reclassification fee. Accurate measurements and correct initial classification prevent this.
PCF stands for pounds per cubic foot, the unit of density used to determine freight class. Calculated as total weight in pounds divided by total volume in cubic feet.
Yes, by reducing shipment dimensions or increasing weight-to-size ratio. Repackaging into tighter boxes, reducing void fill, and palletizing more efficiently increases density and lowers freight class, reducing LTL rate.
Most furniture falls in Class 125 to Class 250, since it is bulky with low density. Flat-pack furniture typically classifies lower (denser) than assembled furniture. Some furniture has a fixed NMFC commodity code overriding density.
Class 50 carries the lowest rates per hundredweight because it represents the densest, most efficiently transported freight. Examples include metal parts, flooring tiles, and heavy machinery components.
All major LTL carriers use the NMFC classification system, so Class 50 means the same across FedEx Freight, UPS Freight, XPO, and others. However, carriers apply their own tariffs on top, so rates differ even for the same class.