Freight Class Calculator

Report an Issue

Help us improve by telling us what went wrong.

Embed this Tool

Customize and copy the embed code for your website.

Freight Class Calculator: Determine Your NMFC Classification Quickly

Shipping freight in the United States? Then you need to know your freight class. The Freight Class Calculator helps you determine the correct National Motor Freight Classification (NMFC) class for your shipment based on its density, stowability, handling characteristics, and liability. Getting the freight class right is essential - an incorrect classification can lead to reclassification fees, billing adjustments, and unexpected shipping costs that eat into your margins.

What Is Freight Class?

The National Motor Freight Traffic Association (NMFTA) developed the NMFC system to standardise freight pricing across the less-than-truckload (LTL) shipping industry. There are 18 freight classes, ranging from Class 50 (the densest, most easily handled goods - like nuts, bolts, and floor tiles) to Class 500 (the lightest, most awkward items - like bags of gold dust or ping pong balls). The higher the class, the more expensive the shipment per unit of weight. The Freight Class Calculator maps your shipment's characteristics to the appropriate class so you know what to expect on your bill of lading.

How Freight Class Is Determined

Four factors influence freight classification. Density is the most important: it is calculated as weight divided by volume in pounds per cubic foot. Denser items generally receive a lower (cheaper) class. Stowability refers to how easily the item can be packed alongside other freight - irregular shapes, hazardous materials, and oversized items are harder to stow. Handling covers the care required during loading and unloading - fragile or awkward items cost more to handle. Liability accounts for the risk of damage, theft, or spoilage. The Freight Class Calculator weighs all four factors, with density as the primary determinant for density-based commodities.

Using the Freight Class Calculator

Enter the weight of your shipment in pounds and its dimensions (length, width, height) in inches. The tool calculates the volume in cubic feet, divides the weight by the volume to get the density, and maps that density to the corresponding freight class using the standard NMFC density breakpoints. For example, a shipment with a density of 12 to 15 pounds per cubic foot falls into Class 65, while a density of 6 to 8 pounds per cubic foot maps to Class 100. The Freight Class Calculator displays the density, the freight class, and a summary of the density tiers for reference.

The 18 Freight Classes at a Glance

Here is a condensed view of the density-based class assignments that the Freight Class Calculator uses. Class 50: 50+ lbs/ft3. Class 55: 35-50. Class 60: 30-35. Class 65: 22.5-30. Class 70: 15-22.5. Class 77.5: 13.5-15. Class 85: 12-13.5. Class 92.5: 10.5-12. Class 100: 9-10.5. Class 110: 8-9. Class 125: 7-8. Class 150: 6-7. Class 175: 5-6. Class 200: 4-5. Class 250: 3-4. Class 300: 2-3. Class 400: 1-2. Class 500: less than 1 lb/ft3. These breakpoints are industry standard, and the calculator applies them automatically.

Why Accuracy Matters: Reclassification Fees

LTL carriers routinely inspect shipments and remeasure them at their terminals. If the actual freight class differs from what was declared on the bill of lading, the carrier will reclassify the shipment and charge the higher rate - often with an additional reclassification or inspection fee on top. This can increase your shipping cost by 20 to 50 percent or more. Using the Freight Class Calculator before shipping ensures your declared class matches reality, protecting you from surprise charges and maintaining a good relationship with your carrier.

Dimensional Weight vs. Freight Class

Do not confuse freight class with dimensional weight pricing used by parcel carriers like UPS and FedEx. Dimensional weight applies a formula (length x width x height / divisor) to determine a billing weight for packages, while freight class is a category-based system for palletised LTL shipments. They are related in that both penalise low-density shipments, but the mechanisms and rate structures are completely different. The Freight Class Calculator is designed specifically for the NMFC freight class system used in LTL shipping.

Tips for Reducing Your Freight Class

Since a lower freight class means lower shipping costs, shippers often look for ways to increase density. Strategies include using smaller packaging that fits the product more tightly, palletising items to maximise the cube utilisation, and consolidating multiple items into a single shipment. Some shippers even redesign their product packaging specifically to achieve a lower freight class - the savings over thousands of shipments per year can be substantial. Use the Freight Class Calculator to model different packaging scenarios before committing to a design.

When Density Alone Is Not Enough

Some commodities have a fixed NMFC class regardless of density because their handling, stowability, or liability characteristics override the density calculation. Electronics, live plants, artwork, and hazardous materials are examples. For these items, the Freight Class Calculator recommends looking up the specific NMFC item number in the NMFTA database rather than relying solely on density. The tool flags common commodity types that require a fixed-class lookup, ensuring you do not inadvertently use the wrong classification.