Freight Class Calculator (NMFC)
This calculator determines the NMFC freight class for your LTL shipment using either the density method (weight and dimensions) or a commodity type lookup. Enter your shipment weight and dimensions to calculate density and map it to the correct class, or select your commodity type from the pre-loaded lookup table.
100% client-side. Inputs stay in your browser (ons-freight-class-inputs).
Final class is determined by the carrier at pickup. This estimate is for quoting purposes.
Freight class
100
Density
9.38 lb/cu ft
Volume
53.33 cu ft
Mid-density freight. Typical for cartoned goods. Rates sit in the middle of the NMFC scale.
Mid-range CWT
500 lbs on 48×40×48 in
NMFC density class table
Your estimated class row is highlighted when using the density method.
| Class | Density (lb/cu ft) |
|---|---|
| 50 | 50 or more |
| 55 | 35 to under 50 |
| 60 | 30 to under 35 |
| 65 | 22.5 to under 30 |
| 70 | 15 to under 22.5 |
| 77.5 | 13.5 to under 15 |
| 85 | 12 to under 13.5 |
| 92.5 | 10.5 to under 12 |
| 100 | 9 to under 10.5 |
| 110 | 8 to under 9 |
| 125 | 7 to under 8 |
| 150 | 6 to under 7 |
| 175 | 5 to under 6 |
| 200 | 4 to under 5 |
| 250 | 3 to under 4 |
| 300 | 2 to under 3 |
| 400 | 1 to under 2 |
| 500 | under 1 |
How does the Freight Class Calculator (NMFC) work step by step?
Input the shipment's total weight in pounds and its dimensions (length, width, height in inches). The calculator computes density in pounds per cubic foot by dividing weight by volume. Density is the primary driver of freight class for most commodities. Shipments with density above 50 pounds per cubic foot typically fall into lower classes (50 to 85), while density below 8 pounds per cubic foot pushes classification into higher classes (125 to 500). Enter the commodity type if it has special handling or liability considerations. Fragile, hazardous, or high-value items may be assigned a higher class than density alone would suggest.
What does a typical Freight Class Calculator (NMFC) result look like?
A pallet of machine parts: 500 lbs, dimensions 48 x 40 x 48 inches. Volume: (48 x 40 x 48) / 1728 = 53.3 cubic feet. Density: 500 / 53.3 = 9.38 lbs/cubic foot. The 9-10.5 range maps to Class 100. A second example: lightweight foam packaging, 50 lbs, 60 x 40 x 40 inches. Volume: 55.6 cubic feet. Density: 0.90 lbs/cubic foot. Below 1: Class 500 (most expensive). Dense, heavy shipments get cheap Class 50. Light, bulky shipments get expensive Class 500.
How are freight classes calculated by density?
The table below shows the 18 NMFC freight class tiers and their density thresholds. Dense, heavy shipments earn low classes (cheap to ship); light, bulky shipments fall into high classes (expensive). Use this as a quick reference when reviewing carrier quotes.
| Class | Density (lb/cu ft) |
|---|---|
| 50 | 50 or more |
| 55 | 35 to under 50 |
| 60 | 30 to under 35 |
| 65 | 22.5 to under 30 |
| 70 | 15 to under 22.5 |
| 77.5 | 13.5 to under 15 |
| 85 | 12 to under 13.5 |
| 92.5 | 10.5 to under 12 |
| 100 | 9 to under 10.5 |
| 110 | 8 to under 9 |
| 125 | 7 to under 8 |
| 150 | 6 to under 7 |
| 175 | 5 to under 6 |
| 200 | 4 to under 5 |
| 250 | 3 to under 4 |
| 300 | 2 to under 3 |
| 400 | 1 to under 2 |
| 500 | under 1 |
For a deeper explanation of how carriers use these tiers, see What is freight class?, how to calculate freight density, and LTL vs. FTL shipping.
What is an NMFC item number?
NMFC stands for National Motor Freight Classification, a standardized system maintained by the National Motor Freight Traffic Association (NMFTA). Every commodity that moves by LTL has an NMFC item number -- a four- to six-digit code that identifies the commodity and its assigned class. The item number appears on the bill of lading and is used by carriers to verify the declared class at the dock. If your carrier requests an NMFC item number, look it up through the NMFTA directory or ask your broker. This calculator uses density to derive class for general freight; commodity-specific NMFC numbers may override the density result.
Frequently asked questions
Why did my carrier reclassify my shipment and charge me more?
Carriers reclassify shipments when the declared class on the bill of lading does not match the actual weight, dimensions, or commodity type upon inspection at the terminal. Common triggers include underestimating dimensions, using the wrong NMFC code for the commodity, or failing to account for packaging that increases total volume. To avoid reclassification, measure and weigh shipments accurately before quoting class, and use the NMFC lookup database to verify the correct commodity code.
Can I negotiate freight class with my carrier?
Freight class itself is set by the NMFTA and is not negotiable. However, you can negotiate a discount off the base class rate or agree to FAK (Freight All Kinds) pricing, where the carrier quotes a flat rate per hundredweight regardless of class. FAK pricing is common for high-volume shippers with predictable commodity mixes and benefits both parties by simplifying billing and reducing reclassification disputes. Small shippers rarely qualify for FAK but can still negotiate percentage discounts off published class rates.
How does packaging affect freight class?
Bulky or inefficient packaging increases volume without adding weight, reducing density and pushing the shipment into a higher class. Using oversized boxes, excessive dunnage, or air-filled protective packaging can move a shipment from class 85 to class 100 or higher. Switching to custom-fit cartons, vacuum packing, or pallet consolidation increases density and lowers class. For high-volume shippers, packaging optimization to achieve density targets for lower freight classes can save 5 to 15 percent on annual freight spend.
What is the difference between freight class and NMFC code?
NMFC code is a detailed commodity classification that maps to a freight class range based on density, stowability, handling, and liability. Each NMFC code may correspond to multiple freight classes depending on density thresholds. For example, NMFC 50 covers auto parts, which can be class 55, 65, or 85 depending on whether density exceeds 35, 22.5, or 13.5 pounds per cubic foot. Always identify both the correct NMFC code for your commodity and the density-based class within that code to ensure accurate rating.
Do all carriers use freight class for pricing?
Most LTL carriers in North America use freight class as the foundation for rate structures, though some publish density-based rates that bypass traditional classification. Parcel carriers (UPS, FedEx) do not use freight class; they price by dimensional weight and service level. Truckload carriers price by mileage and equipment type, not class. International freight (ocean, air) uses volumetric weight formulas rather than NMFC classes. Only domestic LTL shipments require freight class for accurate quoting.
How do I handle freight class for hazardous materials?
Hazardous materials (hazmat) often carry a higher freight class than their density would suggest due to liability, handling, and regulatory compliance costs. Check the NMFC sub-item for your specific hazmat type, and include all required placards, documentation, and packaging certifications on the bill of lading. Carriers may apply hazmat surcharges in addition to the class-based rate. For frequently shipped hazmat, confirm the class and surcharges with your carrier in advance to avoid surprise charges.
Related tools
- Reorder point & EOQ calculator for safety stock and order quantity.
- Commodity storage ROI simulator for hold vs sell decisions.
- Inventory turnover calculator for days on hand and holding cost.
- Feed blending cost optimizer for least-cost rations.
- Wholesale markup calculator for distributor pricing.