NMFC (National Motor Freight Classification) is a standardized freight classification system used to determine shipping rates for LTL (Less-Than-Truckload) freight. It classifies commodities into 18 classes from 50 (lowest cost, densest) to 500 (highest cost, least dense) based on density, stowability, handling, and liability.

What are the 4 factors that determine freight class?

The four transportability characteristics are: (1) Density - weight per cubic foot (PCF), the most critical factor, (2) Stowability - how easily items pack with other freight, (3) Handling - special equipment or care needed, (4) Liability - value and susceptibility to theft or damage.

How do I calculate PCF density for freight class?

Calculate PCF density using this formula: Density (PCF) = Total Weight (lbs) / Total Volume (Cubic Feet). For volume, multiply Length × Width × Height in inches, then divide by 1,728 to convert to cubic feet. Higher density = lower class = lower cost.

What is the most common freight class?

Class 70 and Class 85 are the most common for general freight. Class 70 applies to items with 15-22.5 PCF density (furniture, car parts, food products). Class 85 applies to 12-13.5 PCF density (crated machinery, transmissions).

What happens if I use the wrong freight class?

Using the wrong freight class results in carrier re-classification and re-weigh fees of $50-500 per shipment, plus the difference in shipping rates. A Class 70 shipment incorrectly classified as Class 125 can cost $200-400 extra in penalties and rate adjustments.

Do I include pallet weight in freight class calculation?

Yes, always include pallet weight (typically 30-70 lbs) and pallet dimensions (adds 4-6 inches to height) in your calculations. Excluding the pallet results in incorrect density, wrong classification, and carrier re-class penalties.

What is NMFC? Complete Freight Class Guide (2026)

If you ship Less-Than-Truckload (LTL) freight, understanding the National Motor Freight Classification (NMFC) system is the single most important factor for controlling your costs. Get it wrong, and you face steep re-class penalties ranging from $50 to $500 per shipment.

💡 Quick Takeaway

NMFC classifies freight into 18 classes (50-500) based primarily on density (PCF). Higher density = lower class = lower cost. Use our free calculator to determine your exact class in seconds.

What is NMFC (National Motor Freight Classification)?

The National Motor Freight Classification (NMFC) is a standardized freight classification system developed and maintained by the National Motor Freight Traffic Association (NMFTA). This system provides a uniform way for carriers to price LTL shipments by assigning every commodity a freight class number from 50 to 500.

Think of it as a universal language for freight pricing. Instead of each carrier creating their own classification system, NMFC creates consistency across the industry, making it easier to compare quotes and understand pricing.

The 4 Factors That Determine Freight Class

The NMFC system evaluates commodities based on four key transportability characteristics:

Density (PCF)

Weight per cubic foot. The most critical factor for 95% of shipments.

Stowability

How easily the item can be packed with other freight.

Handling

Level of care and special equipment needed.

Liability

Value of goods and susceptibility to theft or damage.

⚠️ Important Note

While all four factors matter, density is the primary determinant for standard palletized freight. Unless your shipment has unusual handling requirements or exceptionally high value, density alone will determine your freight class.

How to Calculate PCF Density (The Critical Formula)

For most general freight, density is the primary determinant. PCF (Pounds Per Cubic Foot) measures how much a shipment weighs relative to the space it occupies. The higher the density, the lower the class, and typically, the lower the cost.

The formula for density is simple, but must be calculated precisely:

Density (PCF) = Total Weight (lbs) ÷ Total Volume (ft³)

Volume (ft³) = (Length × Width × Height in inches) ÷ 1,728

Step-by-Step Calculation Example:

Example: Standard Pallet Shipment

1. Dimensions: 48" × 40" × 48" (including pallet)
2. Weight: 500 lbs (including 40 lb pallet)
3. Volume: (48 × 40 × 48) ÷ 1,728 = 53.33 ft³
4. Density: 500 lbs ÷ 53.33 ft³ = 9.38 PCF
5. Class: 9.38 PCF = Freight Class 100

Since your dimensions are in inches, you must divide the total cubic inches (L × W × H) by 1,728 (the number of cubic inches in a cubic foot) to get the volume in cubic feet. This is exactly what the CargoTools Calculator does instantly.

Complete NMFC Density-to-Class Mapping Chart

Density (PCF)	Freight Class	Typical Items
50+ PCF	Class 50	Bricks, cement, hardwood flooring
35-50 PCF	Class 55	Bricks on pallets, mortar
30-35 PCF	Class 60	Car parts, bottled beverages
22.5-30 PCF	Class 65	Car accessories, bottled water
15-22.5 PCF	Class 70	MOST COMMON: Food, auto parts, furniture
13.5-15 PCF	Class 77.5	Tires, bathroom fixtures
12-13.5 PCF	Class 85	VERY COMMON: Crated machinery, transmissions
10.5-12 PCF	Class 92.5	Computers, monitors, refrigerators
9-10.5 PCF	Class 100	Boat covers, car covers, canvas
8-9 PCF	Class 110	Cabinets, framed artwork
6-8 PCF	Class 125	Small household appliances
4-6 PCF	Class 150	Auto sheet metal parts
3-4 PCF	Class 175	Clothing, couches, stuffed furniture
2-3 PCF	Class 200	Auto parts, aircraft parts, aluminum table
1-2 PCF	Class 250	Bamboo furniture, mattresses, plasma TVs
< 1 PCF	Class 300-500	Ping pong balls, inflated items

Common Mistakes That Lead to Re-Class Fees

❌

Ignoring Pallet Weight

You must include the ~40-70 lbs of the wooden pallet in your calculation. Excluding it results in incorrect density and wrong classification.

❌

Measuring Pallet Instead of Freight

If a box sticks out 1 inch over the pallet edge, you must measure the box dimensions, not the pallet dimensions. Use extreme dimensions.

❌

Guessing Freight Class

"Class 70" is not a catch-all. If your density is actually 8 PCF, you will be re-classed to 125 and charged $200-400 in penalties plus rate difference.

❌

Rounding Errors

Rounding dimensions or weight before calculating PCF can shift you into the wrong class. Always calculate with precise measurements first.

The Cost Impact of Freight Class

Understanding freight class directly impacts your bottom line. Here's a real-world example of how class affects shipping costs:

Same shipment (500 lbs, 200 miles):

Class 50: $175 (Dense items - lowest cost)

Class 70: $225 (Most common)

Class 100: $295 (+$70 vs Class 70)

Class 125: $380 (+$155 vs Class 70)

Class 200: $625 (+$400 vs Class 70!)

Annual Impact: If you ship 100 pallets per year and misclassify Class 70 freight as Class 125, you're paying an extra $15,500 annually in unnecessary costs, not including re-class penalties.

Use the CargoTools Freight Class Calculator

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What is NMFC? The Complete Guide to Freight Class and Density (2025)