What is freight class
Freight class is a standardized classification system used throughout the Less Than Truckload (LTL) shipping industry to categorize commodities and determine shipping rates. Established and maintained by the National Motor Freight Traffic Association (NMFTA), the National Motor Freight Classification (NMFC) system assigns every type of shipped goods a class number ranging from 50 to 500. These 18 distinct classes serve as a common language between shippers, carriers, and freight brokers, ensuring consistent and fair pricing across the entire LTL industry.
The freight class system exists because LTL shipments share trailer space with cargo from multiple shippers. Unlike full truckload shipping where a single shipper pays for the entire trailer, LTL carriers need a way to fairly allocate costs among different types of freight that occupy varying amounts of space, require different handling procedures, and carry different levels of risk. A pallet of dense steel bolts, for example, takes up far less space relative to its weight than a pallet of foam packaging, even though both might weigh the same. The freight class system accounts for these differences.
Lower freight classes (50 through 70) represent dense, easy-to-handle, low-risk commodities that are the cheapest to ship. Higher classes (300 through 500) represent light, bulky, fragile, or hazardous items that cost significantly more to transport. The difference in shipping cost between Class 50 and Class 500 can be substantial, sometimes varying by a factor of five or more. Understanding your freight class before requesting quotes helps you budget accurately, negotiate better rates, and avoid costly reclassification charges from carriers who inspect shipments and find them incorrectly classified.
Every commodity has a designated NMFC number and associated freight class listed in the NMFC directory. However, many commodities use density-based classification, where the freight class is determined by calculating the shipment's density in pounds per cubic foot. This calculator uses the density-based method, which applies to the majority of general freight shipments.
How freight class is determined
Freight class is primarily determined by four transportation characteristics, with density being the most influential factor for most commodities:
**Density** is the single most important factor and the basis for this calculator. It measures how much space a shipment occupies relative to its weight. The formula is:
\`\`\` Density (lbs/ft³) = Weight (lbs) / Cubic Feet Cubic Feet = (Length x Width x Height in inches) / 1,728 \`\`\`
The number 1,728 converts cubic inches to cubic feet (12 x 12 x 12 = 1,728). Higher density means a lower freight class and lower shipping costs.
**Stowability** refers to how easily freight can be loaded alongside other commodities. Items with irregular shapes, hazardous materials requirements, or those that cannot be stacked reduce trailer utilization and may receive a higher class.
**Handling** considers the care, equipment, and labor required to load and unload the shipment. Freight that requires special equipment, is fragile, or needs careful positioning costs more to handle.
**Liability** accounts for the risk of damage, theft, or causing damage to adjacent freight. Perishable goods, high-value items, and hazardous materials carry higher liability and may be assigned a higher class regardless of density.
Complete freight class table
The 18 NMFC freight classes and their density ranges:
- **Class 50**: 50+ lbs/ft³ — Fits on a standard shrink-wrapped pallet, very dense (e.g., steel bolts, bricks) - **Class 55**: 35-50 lbs/ft³ — Dense commodities like cement, hardwood flooring - **Class 60**: 30-35 lbs/ft³ — Car parts, steel accessories - **Class 65**: 22.5-30 lbs/ft³ — Car parts and accessories, bottled beverages - **Class 70**: 15-22.5 lbs/ft³ — Food items, automobile engines, furniture pieces - **Class 77.5**: 13.5-15 lbs/ft³ — Tires, bathroom fixtures - **Class 85**: 12-13.5 lbs/ft³ — Crated machinery, cast iron stoves - **Class 92.5**: 10.5-12 lbs/ft³ — Computers, monitors, refrigerators - **Class 100**: 9-10.5 lbs/ft³ — Boat and car covers, canvas, wine cases - **Class 110**: 8-9 lbs/ft³ — Cabinets, framed artwork, table saws - **Class 125**: 7-8 lbs/ft³ — Small household appliances, vending machines - **Class 150**: 6-7 lbs/ft³ — Auto sheet metal parts, bookcases - **Class 175**: 5-6 lbs/ft³ — Clothing, couches, stuffed furniture - **Class 200**: 4-5 lbs/ft³ — Auto sheet metal parts, aluminum tables, packaged mattresses - **Class 250**: 3-4 lbs/ft³ — Bamboo furniture, mattresses and box springs, plasma TVs - **Class 300**: 2-3 lbs/ft³ — Wood cabinets, tables, chairs assembled - **Class 400**: 1-2 lbs/ft³ — Deer antlers, lightweight bulky items - **Class 500**: Less than 1 lb/ft³ — Bags of gold fish, ping pong balls, low-density foam
How to use this calculator
1. Measure the length, width, and height of your shipment in inches. Always measure the full dimensions including packaging, pallets, and any protruding parts. If your shipment is on a pallet, measure the pallet dimensions as well. 2. Enter these dimensions into the Length, Width, and Height fields. 3. Enter the total weight of your shipment in pounds, including packaging and pallet weight. 4. The calculator instantly displays your freight class, density in pounds per cubic foot, and total volume. The freight class table below highlights your matching class for easy reference. 5. Use the calculated freight class when requesting LTL shipping quotes from carriers or freight brokers.
Tips for lowering your freight class
Since lower freight classes mean lower shipping costs, there are several strategies to reduce your freight class:
- **Reduce packaging size**: Eliminate excess void space in boxes and crates. The smaller the package dimensions, the higher the density and the lower the class. - **Use denser packaging materials**: Replace foam peanuts with heavier packing materials that add weight without significantly increasing volume. - **Consolidate shipments**: Combining multiple smaller packages into one denser shipment can improve overall density. - **Stack pallets efficiently**: Arrange items to minimize wasted vertical space on the pallet. A well-stacked pallet has higher density than a loosely arranged one. - **Choose the right pallet size**: Use the smallest pallet that safely accommodates your freight. A 48x40 pallet is standard, but a 48x48 pallet for the same weight reduces density. - **Disassemble when possible**: Furniture and equipment that can be flat-packed ship at a higher density than when fully assembled. - **Negotiate with carriers**: If you ship frequently, carriers may offer density-based pricing or class reductions based on your shipping volume and history.
FAQs
Q: What happens if my freight is classified incorrectly? A: Carriers have the right to inspect shipments and reclassify them. If your freight is found to be in a higher class than declared, you will receive a reclassification fee plus the difference in shipping cost. This can significantly increase your total shipping expense, so accurate classification is important.
Q: Does this calculator give the exact NMFC freight class for my commodity? A: This calculator determines freight class based on density, which is the primary factor for most general commodities. However, some specific items have a fixed NMFC class regardless of density due to handling, stowability, or liability concerns. Always verify your specific commodity's NMFC number and class in the official NMFC directory for the most accurate classification.
Q: What dimensions should I measure for freight on a pallet? A: Measure the total dimensions of the shipment as it will be loaded on the truck, including the pallet. If items overhang the pallet edges, use the widest points. If items are stacked above the pallet, measure to the highest point. Carriers calculate density based on the full footprint your freight occupies in the trailer.
Q: How does freight class affect my shipping quote? A: Freight class is one of the primary factors carriers use to calculate LTL shipping rates. A lower class generally means a lower rate per hundredweight (CWT). The difference between adjacent classes can mean a 10-20% price difference, and jumping several classes can double or triple the cost. Other factors like distance, lane density, and accessorial services also affect the final quote.
Q: Can I ship items of different classes on the same pallet? A: Yes, but the carrier may classify the entire shipment at the highest class among the items, or they may apply the density-based class to the combined shipment. When mixing items, calculate the overall density of the combined shipment to estimate the blended class. Some carriers will accept item-level classification if clearly labeled and documented on the bill of lading.
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