Accurately determining the freight class of your shipment is one of the most critical steps in Less-Than-Truckload (LTL) shipping. Whether you are shipping heavy machinery, pallets of consumer goods, or fragile electronics, getting the freight class right ensures you get an accurate quote and avoid costly reclassification fees. Our Freight Class Calculator uses the latest density-based standards (NMFC) to help you instantly identify the correct class for your cargo based on its dimensions and weight.
What is Freight Class?
Freight Class is a standardized system used in the United States LTL shipping industry to categorize commodities transported by truck. It was developed by the National Motor Freight Traffic Association (NMFTA) to establish a fair and consistent pricing structure for carriers and shippers.
Every commodity shipped via LTL is assigned a National Motor Freight Classification (NMFC) code. This code corresponds to a specific freight class, ranging from Class 50 (least expensive) to Class 500 (most expensive).
The classification is based on four primary transportation characteristics:
- Density: The weight per cubic foot. This is the most common factor for general freight.
- Stowability: How easily the item can be stacked or stowed with other freight.
- Handling: The ease or difficulty of loading and unloading the freight.
- Liability: The risk of theft, damage, or damage to other freight (e.g., hazardous materials).
The Importance of Density in Freight Class
In recent years, the LTL industry has shifted heavily towards density-based classification. This means that for many commodities, the freight class is determined primarily by the sheer density of the shipment—how much it weighs relative to the space it occupies.
Density is measured in pounds per cubic foot (PCF). Generally, higher density means a lower freight class and lower shipping cost. Why? Because dense items (like bricks or steel) take up less space on a truck relative to their weight, allowing carriers to fit more revenue-generating weight on the trailer. Conversely, low-density items (like ping pong balls or assembled furniture) take up a lot of space but weigh very little, making them less efficient for the carrier and thus more expensive to ship (higher class).
How to Calculate Density (PCF)
Calculating density is a straightforward process involving three steps. Our calculator does this for you automatically, but it's helpful to understand the math behind it.
- Measure Dimensions: Measure the length, width, and height of your shipment in inches. Be sure to include the pallet and any packaging in your measurements. Always measure to the farthest points.
- Calculate Volume in Cubic Feet: Multiply the length, width, and height to get cubic inches, then divide by 1,728 (the number of cubic inches in a cubic foot).
Volume (ft³) = (Length x Width x Height) / 1,728 - Calculate Density: Divide the total weight of the shipment (in pounds) by the total volume (in cubic feet).
Density (PCF) = Weight (lbs) / Volume (ft³)
Freight Class Density Chart
Once you have the density of your shipment, you can determine the estimated freight class using the standard 18-class system. Keep in mind that specific NMFC codes may override these general density rules, especially for items with unique handling or liability characteristics.
| Density (PCF) | Freight Class | Common Examples |
|---|---|---|
| Less than 1 PCF | Class 500 | Ping pong balls, gold dust, bags of feathers |
| 1 to 2 PCF | Class 400 | Deer antlers, light fixtures |
| 2 to 3 PCF | Class 300 | Model boats, assembled furniture, kayaks |
| 3 to 4 PCF | Class 250 | Mattresses, bamboo furniture, hot tubs |
| 4 to 5 PCF | Class 200 | Aluminum tubing, aircraft parts, sheet metal parts |
| 5 to 6 PCF | Class 175 | Clothing on hangers, padded couches, cabinets |
| 6 to 7 PCF | Class 150 | Auto body parts, bookcases, ATVs |
| 7 to 8 PCF | Class 125 | Small household appliances, exhibition booths |
| 8 to 9 PCF | Class 110 | Framed artwork, table saws, cabinets (knocked down) |
| 9 to 10.5 PCF | Class 100 | Car covers, boat covers, wine, canvas |
| 10.5 to 12 PCF | Class 92.5 | Computers, monitors, refrigerators, inept hardware |
| 12 to 13.5 PCF | Class 85 | Crated machinery, cast iron stoves, transmissions |
| 13.5 to 15 PCF | Class 77.5 | Tires, bathroom fixtures, snowplows |
| 15 to 22.5 PCF | Class 70 | Car engines, food items, auto parts |
| 22.5 to 30 PCF | Class 65 | Books in boxes, bottled beverages, tiles |
| 30 to 35 PCF | Class 60 | Machine parts, hardwood flooring, car accessories |
| 35 to 50 PCF | Class 55 | Bricks, cement, hardwood flooring, synthetic rubber |
| Over 50 PCF | Class 50 | Steel nuts and bolts, steel rods, sand |
Strategies to Lower Your Freight Class and Save Money
Since freight class directly impacts your shipping rates, lowering your class (increasing your density) is one of the most effective ways to reduce logistics costs. Here are several strategies savvy shippers use to optimize their freight:
1. Optimize Packaging
Reducing the dimensions of your shipment without changing the weight increases density. Avoid using pallets that are too large for your cargo. If your boxes hang over the edge of the pallet, you risk damage, but if there is too much empty space on the pallet, you are paying for "air." Use shrink wrap to condense loose items and ensure a tight, compact profile.
2. Crating vs. Palletizing
In some cases, Crating items might be more space-efficient than palletizing, especially for irregularly shaped machinery. A custom crate can reduce the overall "cubic feet" of the shipment compared to a standard pallet with overhangs or awkward stacking.
3. Knock Down (KD) Assembly
"Knocked Down" or "KD" refers to items that are disassembled for shipping. Shipping a table fully assembled (Class 250 or 300 due to low density) is significantly more expensive than shipping it flat-packed (Class 85 or 70). Whenever possible, ship products in their most compact, disassembled state.
4. Accurate Weighing and Measuring
Never guess your dimensions or weight. Carriers use advanced dimensioners (lasers) to verify freight. If you declare a density of 15 PCF (Class 70) but the carrier measures it at 11 PCF (Class 92.5), you will be hit with a "Reclassification Fee." These fees can be substantial. Use our calculator to double-check your math before booking.
The Impact of NMFC Updates on Your Business
The National Motor Freight Traffic Association (NMFTA) updates the NMFC classification codes multiple times a year. These updates can be minor tweaks or massive overhauls that shift entire product categories from one class to another.
Failure to stay updated can be expensive. If you continue using an old code for a product that has been reclassified to a higher density tier, you will face chronic reclassification fees. To mitigate this risk, successful logistics managers subscribe to NMFTA updates or work with a 3PL (Third-Party Logistics) provider who manages this data for them.
Dispute Resolution: What to Do When Reclassified
Getting hit with a "Weight and Inspection" (W&I) certificate that changes your freight class and doubles your bill is frustrating. However, you can dispute it if you have the right evidence.
- Keep Your Proof: Always take photos of your shipment on the scale and with the tape measure visible before it leaves your dock.
- Check the Certificate: Review the carrier's W&I certificate carefully. Did they measure the pallet? Did they transpose a number? Human error is common on the dock.
- File a Claim: Submit your photos and the original Bill of Lading (BOL) to the carrier's dispute team. If the visual evidence proves your density calculation was correct, they will often reverse the charge.
Technology's Role in Freight Classification
The days of guessing are over. Modern warehouses use "dimensioners"—automatic scanning rigs that calculate the weight and volume of a pallet in seconds.
Shippers are now adopting this technology too. By using our online Freight Class Calculator in conjunction with reliable warehouse data, you can create a "digital twin" of your shipment. This data parity ensures that what you quote is exactly what you pay, removing the friction from LTL shipping.
Navigating NMFC Codes
While density is the primary driver, the specific NMFC code is the ultimate authority. Some items have fixed classes regardless of density. For example, specific hazardous materials or extremely high-value items may have a set class that density cannot change.
Always consult the official NMFC directory or ask your freight broker to confirm the correct implementation of the code. Using the wrong NMFC code is a common reason for billing adjustments.
Comparing LTL Carriers
Not all carriers price freight classes the same way. Carrier A might offer a steep discount on Class 50 freight but possess higher rates for Class 150. Carrier B might specialize in lightweight, bulky freight and offer better rates for Class 250.
When you use our Shipping Calculator, you can get quotes from multiple carriers to see how your specific freight class affects the final price across the market. You can also compare rates directly with our FedEx Calculator or UPS Calculator for smaller shipments.
Frequently Asked Questions
For more tools to help you manage your logistics, check out our USPS Shipping Calculator for parcel shipments or verify your Freight Class before every LTL booking. Accurate data is the key to controlling your supply chain costs.