Understanding Shipping Costs: How Is Freight Class Determined

What Is Freight Class?

As the number of loads increased exponentially, shippers and carriers called for a standardized classification system to determine shipping costs. Currently known as the National Motor Freight Classification or simply freight classes, this system categorizes different types of freight based on specific criteria, ensuring that shipments are handled appropriately and priced fairly.

Freight classes allow for effective cost management, helping avoid unexpected charges and ensuring that goods are transported efficiently. Accurate classification benefits both shippers and carriers by providing clarity and consistency in the shipping process.

Freight classes impact shipping rates, transit times, and the overall logistics strategy. Applying the correct freight class streamlines shipping operations, reduces costs, and gains customer satisfaction.

Factors Influencing Freight Classification

Determining the correct freight class involves evaluating four main factors: density, stowability, handling, and liability. Each of these factors influences how freight is classified and, consequently, how much it costs to ship.


Density refers to the weight of the shipment relative to its size. It is calculated by dividing the weight by the volume of the shipment. Higher-density items tend to cost less to ship per unit of weight because they take up less space. Conversely, low-density items take up more space and are generally more expensive to ship.


Stowability assesses how easily freight can be stored and transported alongside other shipments. Items that are irregularly shaped or bulky can be challenging to stow and may require special handling, increasing shipping costs. Items that are easy to stack and store efficiently reduce these complexities and costs.


Handling considers the ease or difficulty involved in moving the freight. Items that require special equipment or precautions during loading and unloading are classified differently than those that can be handled with standard procedures. Fragile or awkward items may increase the handling complexity and, thus, the shipping cost.


Liability addresses the risk associated with shipping the freight, including the potential for damage, theft, or loss. High-value items or those prone to damage are classified with higher liability, which can increase shipping insurance costs and require additional security measures.

Understanding the Freight Class Categories

Freight classes range from Class 50 to Class 500, with each category representing different types of goods based on density, stowability, handling, and liability. These classes help determine shipping rates and ensure that freight is transported efficiently.

Class 50(over 50 lbs per cubic foot)

Class 50 includes the heaviest and densest items, such as bricks. These goods are compact and occupy minimal space, making them cheaper to ship.

Class 70(15-22.5 lbs per cubic foot)

Car parts often fall into Class 70. These items are moderately dense and can be stowed easily, leading to relatively low shipping costs.

Class 85(12-13.5 lbs per cubic foot)

Furniture is typically classified under Class 85. Although it may be bulky, its handling and stowability are manageable, maintaining reasonable shipping rates.

Class 100(9-10.5 lbs per cubic foot)

Class 100 includes items like computers. These goods have an average density and require careful handling, impacting their shipping cost.

Class 125(7- 8 lbs per cubic foot)

Clothing is usually categorized under Class 125. Its lightweight nature and ease of handling make it moderately priced for shipping.

Class 150(6-7 lbs per cubic foot)

Machinery often falls into Class 150. These items are heavier and may require special handling, affecting their classification and cost.

Class 200(4-5 lbs per cubic foot)

Bicycles are classified under Class 200. They are bulky and require careful handling, increasing their shipping costs.

Class 250(3-4 lbs per cubic foot)

Bulky plastic items are typically in Class 250. Their size and handling requirements contribute to higher shipping rates.

Class 300(2-3 lbs per cubic foot)

Large appliances, such as refrigerators, fall under Class 300. Their size and weight necessitate special handling, increasing shipping costs.

Class 400(1-2 lbs per cubic foot)

Wooden crates are often in Class 400. They are large, potentially heavy, and require careful handling, leading to higher shipping costs.

Class 500(less than 1 lbs per cubic foot)

Class 500 includes items like ping pong balls. These goods are light but take up a lot of space, resulting in the highest shipping rates.

How to Calculate the Correct Freight Class

Determining the correct freight class for your shipment is essential for calculating an accurate shipping rate. This primarily refers to determining the shipment’s density, a major factor in freight classification. Here is a step-by-step guide:

Step 1: Measure the Weight

First, measure the total weight of your shipment. Use a scale that provides an accurate reading, as incorrect weight can lead to misclassification.

Step 2: Measure the Volume

Next, measure the dimensions of your shipment. You need the length, width, and height in inches. Multiply these dimensions together to get the volume in cubic inches.

Step 3: Convert Volume to Cubic Feet

Convert the volume from cubic inches to cubic feet by dividing the total cubic inches by 1,728 (since there are 1,728 cubic inches in a cubic foot).

Step 4: Calculate the Density

Now, calculate the density by dividing the weight (in pounds) by the volume (in cubic feet).

Step 5: Determine the Freight Class

Once you have the density, use a freight class chart to determine the corresponding class. Higher density usually means a lower freight class, which results in lower shipping costs.

Tips for Accurate Classification

Stowability: Ensure your items are easy to stack and store. Irregular shapes or hazardous materials can affect stowability and class.

Handling: Consider how your items will be handled. Fragile or awkward items may need special equipment, affecting their classification.

Liability: Assess the risk of damage or theft. High-value or easily damaged items typically fall into higher classes.

Tips for Reducing Shipping Costs Through Freight Class Optimization

Optimizing your freight class can lead to significant savings on shipping costs. Here are some practical tips to help you achieve this goal:

Consolidate Shipments

Combining smaller shipments into a single, larger one can increase the overall density, potentially lowering your freight class. Higher density often translates to lower costs per unit of weight.

Use Efficient Packaging

Opt for sturdy, compact packaging that minimizes wasted space. Properly packed goods are denser and easier to stow, reducing both shipping costs and the risk of damage.

Negotiate with Carriers

Discuss your shipping needs with carriers to explore potential discounts for regular, high-volume shipments. Carriers may offer better rates if you consistently provide well-classified freight.

Regularly Review Freight Class

Freight classifications can change over time due to changes in packaging or product specifications. Regularly audit your freight class to ensure it accurately reflects your current shipping practices.

Consult Specialists

Consulting with logistics experts can provide valuable insights. For example, Carolina Logistics specialists can audit your shipments, identify misclassifications, and suggest ways to optimize your freight class. Their expertise can help you find cost-saving opportunities and ensure compliance with shipping regulations.

Use Technology

Invest in software solutions that automate the classification process. These tools can help you accurately determine the correct freight class, reducing errors and ensuring consistent cost savings.

Maximizing Efficiency in Freight Shipping

Understanding and accurately determining your freight class is a must for managing shipping costs effectively. By considering factors like density, stowability, handling, and liability, you can ensure that your shipments are correctly classified, leading to optimized shipping rates and smoother logistics operations.

Reviewing your current shipping strategies in light of this information can uncover potential cost-saving opportunities. Regular audits, efficient packaging, and consulting with logistics specialists, such as those at Carolina Logistics, can further enhance your freight shipping efficiency.

Implementing these practices reduces costs and improves overall operational efficiency, leading to better service for your customers. Make sure to keep your freight classification up-to-date and leverage expert advice to stay ahead in the logistics game.