Freight Guide
LTL Shipping Guide: Understanding Freight Classes and Why They Matter
Shipping a large or heavy products doesn’t have to be confusing. Many small business owners and the e-commerce sellers struggle with freight classes, unsure why they matter or how they affect costs. This guide will make it simple to understand, helping you plan shipments efficiently and avoid unnecessary fees.
Why Freight Classes Are Important
Freight class directly influences your shipping costs. If your shipment is misclassified, carriers may adjust the price later, leading to unexpected charges. Correct classification helps you save money, prevent delays, and ship with confidence.
Whether you’re sending inventory to Amazon, Walmart, or a Shopify store, knowing the freight class ensures your products move smoothly through the LTL network.
How Freight Density Class Is Calculated
Let’s walk through an example to make it simple. Imagine a pallet measuring 40″ × 48″ × 48″, weighing 425 pounds.
Step 1: Calculate Volume
Multiply the dimensions:
40 × 48 × 48 = 92,160 cubic inches
Convert cubic inches to cubic feet:
92,160 ÷ 1,728 = 53.33 cubic feet
Step 2: Calculate Density
Divide weight by volume:
425 ÷ 53.33 = 7.97 lbs per cubic foot
Step 3: Determine Freight Class
Compare the density to the NMFC density chart: a density between 7 and 8 corresponds to freight class 125.
| Density (lbs/ft³) | NMFC Freight Class |
|---|---|
| 50+ | 50 |
| 35–49.99 | 55 |
| 30–34.99 | 60 |
| 22.5–29.99 | 65 |
| 15–22.49 | 70 |
| 13.5–14.99 | 77.5 |
| 12–13.49 | 85 |
| 10.5–11.99 | 92.5 |
| 9–10.49 | 100 |
| 8–8.99 | 110 |
| 7–7.99 | 125 |
| 6–6.99 | 150 |
| 5–5.99 | 175 |
| 4–4.99 | 200 |
| 3–3.99 | 250 |
| 2–2.99 | 300 |
| 1–1.99 | 400 |
| <1 | 500 |
Freight Classes Explained
Freight classes are standardized categories used in LTL shipping to describe shipment characteristics like density, handling, and space usage. The NMFTA created this system so all carriers follow the same rules, making shipping consistent across the U.S.
- Lower classes (50–60): Dense, compact shipments that cost less to ship.
- Higher classes (150–500): Light or bulky shipments that take up more space and cost more.
How Density Affects Shipping Cost
Density is the weight of your shipment divided by the space it occupies.
- Dense shipments: Stack easily, use space efficiently, lower freight class, lower cost.
- Light or bulky shipments: Take more trailer space, higher freight class, higher cost.
Basic Density Formula:
Density = Total Weight ÷ Total Cubic Feet
To find cubic feet: multiply length × width × height in inches, then divide by 1,728.
Who Needs to Understand Freight Classes?
Freight classification matters for anyone shipping pallets or large packages:
- E-commerce sellers sending inventory to Amazon FBA, Shopify, Etsy, Walmart.
- Manufacturers, wholesalers, distributors moving products between warehouses.
- Small business owners and virtual assistants managing multiple shipments.
Where Freight Classification Is Used
Freight classes apply to LTL shipments, larger than parcel deliveries but smaller than full truckloads.
- Major carriers: FedEx Freight, UPS Freight, SAIA, Estes, DHL
- Retail and e-commerce supply chains rely on this system.
- Third-party LTL booking platforms: FreightQuotes, UniShippers, Freightos
Knowing your freight class, density, and volume makes these tools more effective and reduces errors.
Using Density Tools for Shipping
Online freight calculators simplify the process:
- Enter pallet dimensions and weight.
- Instantly get freight class, density, and volume.
- Prepare accurate shipping documents and avoid billing corrections.
- Ensure smooth shipments across carriers and third-party platforms.
Common Shipping Terms
LTL (Less-Than-Truckload):
- Multiple businesses share one trailer. Affordable for smaller pallet shipments.
FTL (Full Truckload):
- Entire truck dedicated to one shipment. Faster transit for very large shipments.
SPD (Small Parcel Delivery):
- Individual lightweight packages shipped through parcel carriers, common for e-commerce orders.
Final Thoughts
Freight classification is crucial for shipping efficiency and cost control. Calculating density and freight class before booking shipments helps businesses avoid mistakes, save money, and plan effectively.
Whether you ship for Amazon, Shopify, Etsy, Walmart, or as a manufacturer or distributor, knowing your freight class ensures smoother operations and fewer surprises.