Why Freight Class Matters in LTL Shipping
Freight class is one of the most important factors in determining LTL shipping costs. In 2025, with tighter regulations and more advanced pricing models, getting your freight class right is no longer optional—it’s essential. Freight class directly impacts your rate, your risk of audits, and even how your goods are handled during transit. Using a trusted LTL partner like TrexShipping helps you navigate classification with greater accuracy and fewer surprises.
What Is Freight Class in the NMFC System?
The National Motor Freight Classification (NMFC) system assigns a numerical value to freight based on density, stowability, handling, and liability. The class number—ranging from 50 to 500—affects the rate per pound. Lower classes generally apply to dense, easy-to-ship freight, while higher classes are for bulky, fragile, or difficult-to-handle goods.
How NMFC Class Affects LTL Rates
A change from class 100 to class 150 can mean a 25–40% increase in price. This is why accurate freight class lookup is critical. TrexShipping provides a free freight class estimator tool built into every quote request to help shippers avoid cost surprises.
Using Weight and Size to Calculate Freight Class
One of the most reliable ways to determine your LTL freight class is by calculating the density of your shipment, using its weight and dimensions. To calculate freight density: divide the total weight in pounds by the volume in cubic feet. First multiply the length, width, and height (in inches), then divide by 1,728 to convert to cubic feet. Then divide weight by this figure. TrexShipping’s quote system automatically performs this calculation when you enter shipment specs into the online LTL calculator.
Freight Class Table Based on Density (2025)
In general, these are the class guidelines based on density:
Freight Class by Pounds per Cubic Foot
– 50: Over 50 lbs/ft³
– 55–85: 35 to 15 lbs/ft³
– 100–125: 15 to 8 lbs/ft³
– 150–250: 6 to 1 lbs/ft³
– 400–500: Less than 1 lb/ft³
TrexShipping uses this model to help users identify and apply the correct freight class. Visit their freight class lookup reference when preparing quotes.
Other Factors That Influence Freight Class
Beyond density, three other characteristics can influence classification: stowability, handling, and liability.
Handling Difficulty
If your freight is fragile, requires special equipment, or has unusual shapes, carriers may classify it at a higher class even if density is low. TrexShipping’s partial shipment guidance includes packaging and labeling tips to avoid reclassification due to handling concerns.
Stowability Concerns
Hazardous materials, irregular shapes, or items that can’t stack well can be classified higher. These issues are flagged during the Trex quote process, letting you adjust your shipment for better rates.
Common Freight Class Examples by Product Type
Understanding where your product fits can make quoting much faster. Below are general categories:
Sample Freight Classes
– Class 70: Machinery, metal hardware
– Class 125: Wood furniture, cabinets
– Class 200: Upholstered chairs, mattresses
– Class 300+: Lightweight or fragile items
For a complete list, TrexShipping’s freight class chart breaks down the most common NMFC codes by product.
What Happens If You Use the Wrong Freight Class?
Incorrect classification can lead to costly re-weigh and reclass fees. Carriers may delay or reject freight if discrepancies are large. These charges can often be double what you expected to pay.
Preventing Reclass Fees
TrexShipping minimizes this risk by validating shipment specs in their online quoting process and cross-referencing freight classes with carrier standards. Each year, the NMFTA (National Motor Freight Traffic Association) updates classifications. For 2025, changes include reclassing select consumer electronics, pre-assembled furniture, and some e-commerce bulk items.
TrexShipping regularly updates their tools to reflect the latest classification rules. Users submitting quote requests will automatically see updated class suggestions based on current NMFC standards.
Using Freight Class Lookup Tools vs Manual Estimation
Manual estimation can be risky if you’re unfamiliar with density calculations or NMFC definitions. Online lookup tools reduce guesswork and improve accuracy. Trex’s freight class estimator accounts for product type, packaging, density, and special handling requirements—all in one quote form. Freight class can affect how much liability a carrier assumes and what’s covered under their damage policy.
Better Classification Means Stronger Claims
If your freight is misclassified and gets damaged, carriers may deny claims. TrexShipping’s insurance services work best when accurate class data is provided.
Best Practices When Submitting LTL Class Info
Before submitting any LTL quote, double-check dimensions and weight using a certified scale and measuring tool. Convert inches to feet accurately when calculating volume.
Tips for First-Time Shippers
Use sample class data from past shipments, confirm with suppliers, or rely on tools from TrexShipping to avoid misclassification. Always round dimensions up to the nearest inch and include all packaging in the final measurement.
How TrexShipping Simplifies Freight Class Lookup
TrexShipping’s platform is built for clarity. Their quote tool provides automated class suggestions, guides for new users, and customer support if questions arise.
One-Stop Quoting and Classification
Trex’s quote system combines real-time pricing with NMFC-based class lookups so you can book shipments with confidence.
Conclusion: Master Freight Class to Lower Costs and Avoid Issues
Understanding how weight and size affect freight class helps businesses control LTL shipping costs and prevent costly errors. Whether you’re shipping furniture, hardware, or consumer goods, accurate classification ensures smooth logistics and fair pricing.
Start Quoting Smarter with TrexShipping
Visit the LTL freight services page or try the quote calculator today to lookup your freight class by weight and size in seconds.