Freight Class Calculator
How Freight Class Works
Freight class is the standardized pricing category used by LTL (Less Than Truckload) carriers to determine shipping rates. The National Motor Freight Traffic Association (NMFTA) maintains the National Motor Freight Classification (NMFC) system, which assigns classes from 50 (lowest cost, densest freight) to 500 (highest cost, lightest freight). Every product shipped via LTL in North America is classified using this system.
The NMFC system evaluates four characteristics to assign a class: density, handling, stowability, and liability. Density is the most heavily weighted factor for the majority of commodities. Shippers, logistics managers, and freight brokers use freight class calculators to estimate costs before requesting carrier quotes. According to the American Trucking Associations, LTL shipping accounts for approximately $60 billion in annual U.S. freight revenue, making accurate classification critical for cost control.
Knowing your freight class before contacting carriers helps you budget accurately, compare quotes, and avoid costly reclassification fees. Carriers may inspect shipments and reassign the class if the actual density differs from what was declared, often adding a fee of $50-$200 per reclass. Using our Dimensional Weight Calculator alongside this tool gives you a complete picture of your shipment's pricing factors.
The Freight Class Formula
Freight class is determined primarily by density, which is calculated using the standard formula defined by the NMFTA:
Density = Weight (lbs) / Volume (cubic feet)
To find volume in cubic feet: Volume = (Length x Width x Height) / 1,728, where all dimensions are in inches.
Worked example: A shipment weighing 500 lbs measures 48" x 40" x 36". Volume = (48 x 40 x 36) / 1,728 = 40 cubic feet. Density = 500 / 40 = 12.5 lbs/cu ft, which falls into Class 85 (density range 12.0-13.5 lbs/cu ft). A carrier quoting $15 per hundredweight (cwt) for Class 85 would charge: 500 / 100 x $15 = $75 for this shipment.
Key Terms You Should Know
- LTL (Less Than Truckload): A shipping method where multiple shippers share trailer space. LTL is used when a shipment weighs between 150 and 15,000 pounds and does not require a full trailer.
- NMFC Code: A 6-digit commodity code assigned by the NMFTA to every product type. The code determines the freight class. Some codes have fixed classes regardless of density.
- Hundredweight (CWT): A unit of 100 pounds used in LTL rate tables. Carriers quote rates as dollars per CWT for each freight class.
- Density-Based Classification: A classification method where freight class is determined solely by the shipment's pounds-per-cubic-foot ratio, rather than by the specific commodity being shipped.
- Reclass Fee: A penalty charged when a carrier inspects a shipment and determines the actual freight class differs from the class declared by the shipper. Fees typically range from $50 to $200.
Freight Class Density Chart
The NMFTA defines 18 freight classes based on density thresholds. According to industry data from FreightQuote, approximately 70% of all LTL shipments fall between Class 55 and Class 125. The table below shows each class with its density range and typical commodity examples.
| Freight Class | Density (lbs/cu ft) | Typical Commodities |
|---|---|---|
| 50 | 50+ | Sand, gravel, steel plates |
| 55 | 35-50 | Bricks, cement, hardwood flooring |
| 60 | 30-35 | Car parts, bottled beverages |
| 65 | 22.5-30 | Car accessories, boxed food |
| 70 | 15-22.5 | Automotive engines, food items |
| 85 | 12-15 | Crated machinery, cast iron stoves |
| 100 | 9-12 | Boat covers, wine cases, caskets |
| 125 | 7-9 | Small appliances, exhibit materials |
| 150 | 6-7 | ATV/motorcycle cases, bookcases |
| 175 | 5-6 | Clothing, couches, stuffed furniture |
| 200 | 4-5 | TVs, aircraft parts, aluminum tables |
| 250 | 3-4 | Mattresses, plasma screens, bamboo furniture |
| 300 | 2-3 | Wood cabinets, model boats, chassis |
| 400 | 1-2 | Deer antlers, light fixtures |
| 500 | < 1 | Bags of gold dust, ping pong balls |
Practical Examples
Example 1 -- E-commerce retailer shipping electronics: A pallet of boxed laptops weighing 800 lbs measures 48" x 40" x 48". Volume = (48 x 40 x 48) / 1,728 = 53.3 cu ft. Density = 800 / 53.3 = 15.0 lbs/cu ft, qualifying for Class 70. At a rate of $12/cwt, the freight cost is 8 x $12 = $96.
Example 2 -- Furniture manufacturer: A shipment of unboxed office chairs weighing 350 lbs measures 48" x 48" x 60". Volume = (48 x 48 x 60) / 1,728 = 80 cu ft. Density = 350 / 80 = 4.4 lbs/cu ft, placing it in Class 200. At $28/cwt, the cost is 3.5 x $28 = $98. By flat-packing the chairs into two smaller boxes, the volume drops to 45 cu ft and density rises to 7.8 lbs/cu ft (Class 125), reducing the rate to $18/cwt and the cost to $63 -- a 36% savings.
Example 3 -- Food distributor: A pallet of canned goods weighing 1,200 lbs fits on a 48" x 40" x 40" pallet. Volume = 44.4 cu ft. Density = 27.0 lbs/cu ft, easily qualifying for Class 65. This is one of the most cost-effective freight classes for food distribution. Use our Container Load Calculator to optimize full-pallet loads.
Tips to Reduce LTL Shipping Costs
- Maximize density: Use the smallest box that safely fits your product. Eliminate void fill where possible. Dense shipments always get lower classes and cheaper rates.
- Palletize properly: Stack items tightly, shrink-wrap pallets, and keep loads within the pallet footprint. Overhang invites damage claims and handling surcharges.
- Measure accurately: Always measure the full pallet footprint including packaging. Underestimating dimensions leads to reclass fees that can exceed the original freight charge.
- Consider density-based exceptions: The NMFTA allows shippers to apply for density-based classification on certain commodity codes. This can be worthwhile for high-volume shippers whose products straddle a class boundary.
- Consolidate shipments: Combining multiple light shipments into a single denser pallet can drop the overall class by one or two tiers, producing savings of 15-30%.
- Negotiate with carriers: Carriers offer discounts based on volume commitments, lane consistency, and shipper history. Get quotes from at least three carriers for every lane.
LTL Industry Trends and Data
The U.S. LTL market generated approximately $60 billion in revenue in 2024, according to the American Trucking Associations. Average LTL rates increased 3-5% year-over-year through 2025, driven by driver shortages and fuel surcharges. The average fuel surcharge as of early 2026 ranges from 25-35% of the base rate, depending on diesel prices. Accessorial charges (liftgate, residential delivery, inside delivery) add $50-$150 per service. Understanding freight class is the first step to controlling these costs, as the base rate per CWT varies by 300-500% between Class 50 and Class 500.
Frequently Asked Questions
What is the most common freight class?
Class 70 (density 15+ lbs per cubic foot) and Class 85 (density 12-15 lbs per cubic foot) are among the most common freight classes for general merchandise. According to the NMFTA, food products, automotive parts, and boxed consumer goods frequently fall in the Class 55-85 range. These classes represent dense, easily handled freight that carriers can stack and transport efficiently. If your shipment consistently lands in this range, you can negotiate volume discounts with carriers based on predictable class assignments.
Does freight class affect shipping cost?
Freight class has a major impact on LTL shipping costs. Moving from Class 100 to Class 70 can reduce freight charges by 20-40%, depending on the carrier and lane. Lower classes indicate denser, easier-to-handle freight that carriers prefer because it uses truck space more efficiently. The American Trucking Associations reports that LTL carriers base their rate tables directly on NMFC class, so even a one-step class reduction can produce significant savings on high-volume shipments. For a 1,000-pound shipment, the rate difference between Class 100 ($20/cwt) and Class 70 ($12/cwt) is $80 per shipment.
How can I lower my freight class?
The most effective way to lower your freight class is to increase shipment density. Use the smallest packaging possible, stack items tightly on pallets, and eliminate wasted space inside boxes. Shrink-wrapping pallets improves stowability scores. Some products can be reclassified by applying for a density-based exception through the NMFTA. Consolidating multiple lightweight items into a single denser shipment can move you from Class 150 to Class 85, saving 30% or more on freight charges. Always verify your measurements using our Cubic Feet Calculator before requesting quotes.
What is the difference between freight class and NMFC commodity code?
Freight class is the pricing tier (50 to 500) that determines your LTL shipping rate. NMFC commodity codes are specific 6-digit identifiers assigned to every product type by the National Motor Freight Traffic Association. The commodity code determines the freight class, but the relationship is not always density-based. Some items have fixed classes regardless of packaging. For example, hazardous materials or fragile goods may be assigned higher classes due to handling and liability factors rather than density. You can look up commodity codes at the NMFTA ClassIT tool.
What are the four factors that determine freight class?
The NMFC system assigns freight classes based on four characteristics: density (weight per cubic foot), handling (ease of loading and unloading), stowability (how well the freight fits with other cargo), and liability (value, fragility, and risk of damage or theft). Density is the most heavily weighted factor for most commodities. A pallet of steel parts at 40 lbs per cubic foot qualifies for Class 50, while lightweight foam at 2 lbs per cubic foot falls into Class 300. For oddly shaped or hazardous items, handling and liability may override density in the classification.
How do I measure freight density correctly?
Freight density is calculated by dividing the total shipment weight (in pounds) by the total volume (in cubic feet). To find cubic feet, multiply the length, width, and height of the shipment (all in inches), then divide by 1,728. Always measure the full footprint of the pallet, including any overhang or irregular shapes. Carriers will re-measure if your declared dimensions appear incorrect. For example, a 500-pound shipment measuring 48 x 40 x 36 inches occupies 40 cubic feet, giving a density of 12.5 lbs/cu ft (Class 85). Use our Pallet Calculator to plan optimal stacking configurations.