Compare Freight Classes
The NMFC system uses 18 freight classes (50-500) based on density, stowability, handling, and liability. Lower classes (50-85) represent dense, easy-to-ship items with lower rates, while higher classes (150-500) cover lighter, bulkier freight that costs more. Use this tool to compare any two classes side-by-side—see density ranges, NMFC code counts, and relative shipping costs to find optimization opportunities for your shipments.
Class 70 vs Class 100
Key Differences
- Class 70 requires higher density (15-22.5 lbs/ft³) compared to Class 100 (9-10.5 lbs/ft³)
- Shipping Class 70 is typically 30-40% cheaper than Class 100
- Class 70 has 84 more NMFC codes than Class 100
What is Freight Class?
Freight class is a standardized classification system established by the National Motor Freight Traffic Association (NMFTA) to categorize commodities for LTL (Less Than Truckload) shipping. The system uses 18 different classes, ranging from Class 50 (lowest cost) to Class 500 (highest cost).
The Four Classification Factors
- Density - Weight per cubic foot (most important)
- Stowability - How easily items stack and store
- Handling - Special equipment or care needed
- Liability - Value, fragility, and theft risk
Why Classification Matters
- Determines your shipping rate per CWT
- Wrong class = reclassification fees
- Affects carrier acceptance of shipments
- Impacts insurance and liability coverage
How Freight Class Affects Shipping Cost
Lower freight classes indicate denser, easier-to-handle freight that costs less to ship. Higher classes represent lighter, bulkier, or more fragile items that take up more trailer space relative to their weight.
Cost Impact: Adjacent classes differ by 10-15%. The gap between Class 50 and Class 500 can exceed 400%. For a 500 lb shipment, choosing the wrong class could cost $100-$300 extra.
Lower Classes (50-85) = Lower Cost
- Dense items: steel, machinery, bricks
- Easy to stack and handle
- Efficient use of trailer space
- Lower damage risk
Higher Classes (150-500) = Higher Cost
- Light items: furniture, electronics, clothing
- Difficult to stack or fragile
- Takes more space for less weight
- Higher damage/liability risk
How to Calculate Your Freight Class
Density is the primary factor for most commodities. Calculate it using this formula:
Density Formula: Weight (lbs) ÷ [Length × Width × Height (inches) ÷ 1728] = lbs per cubic foot
Example: A 150 lb shipment measuring 48" × 40" × 36" = 150 ÷ (48×40×36÷1728) = 150 ÷ 40 = 3.75 lbs/ft³ → Class 250
After calculating density, match it to the appropriate class range in the table below. Remember that handling requirements, stowability issues, or high-value items may bump your class higher regardless of density.
All 18 Freight Classes at a Glance
| Class | Density (lbs/ft³) | Typical Items | Relative Cost |
|---|---|---|---|
| 50 | 50+ | Steel, heavy machinery, nuts & bolts | Lowest |
| 55 | 35-50 | Bricks, cement, hardwood flooring | Very Low |
| 60 | 30-35 | Car accessories, bottled beverages | Low |
| 65 | 22.5-30 | Car parts, bottled drinks, books | Below Average |
| 70 | 15-22.5 | Auto parts, food items, machinery | Average |
| 77.5 | 13.5-15 | Tires, bathroom fixtures | Average |
| 85 | 12-13.5 | Crated machinery, cast iron stoves | Slightly Above |
| 92.5 | 10.5-12 | Computers, monitors, refrigerators | Above Average |
| 100 | 9-10.5 | Boat covers, car covers, wine cases | Above Average |
| 110 | 8-9 | Cabinets, framed artwork, table saws | Moderate High |
| 125 | 7-8 | Small household appliances | Moderate High |
| 150 | 6-7 | Auto sheet metal, bookcases | High |
| 175 | 5-6 | Clothing, couches, stuffed furniture | High |
| 200 | 4-5 | Auto sheet metal parts, aircraft parts | Very High |
| 250 | 3-4 | Bamboo furniture, mattresses, plasma TVs | Very High |
| 300 | 2-3 | Wood cabinets, tables, chairs | Very High |
| 400 | 1-2 | Deer antlers, lightweight fixtures | Extremely High |
| 500 | <1 | Ping pong balls, gold dust, bags of feathers | Highest |
Tips for Choosing the Right Freight Class
Selecting the correct freight class is crucial for avoiding unexpected fees and ensuring smooth shipping operations. Here are key strategies to get it right:
Measure Accurately
- Use the longest, widest, and tallest dimensions
- Include packaging, pallets, and protrusions
- Round up to the nearest inch
- Weigh on a calibrated scale
Document Everything
- Keep photos of packaged shipments
- Record exact dimensions and weights
- Save BOL copies with classification
- Note any special handling requirements
Pro Tip: When in doubt, consult the official NMFC directory for your specific commodity. Generic density-based classification can be overridden by commodity-specific rules.
Common Classification Mistakes to Avoid
These errors cost shippers thousands in reclassification fees and delayed shipments every year:
Measurement Errors
- Not including packaging - Always measure the total shipping unit
- Using inside dimensions - Use outside box dimensions
- Ignoring irregular shapes - Use the smallest cube that contains the item
Classification Errors
- Assuming density alone determines class - Other factors matter
- Using outdated NMFC codes - Codes change quarterly
- Guessing instead of verifying - Check the NMFC directory
When Carriers Reclassify Your Shipment
Carriers have the right to inspect and reclassify freight. Understanding this process helps you avoid surprises:
Reclassification Process: Carriers may inspect shipments at origin, destination, or cross-docks. If the actual class differs from what's on the BOL, they'll adjust the rate and charge back the difference plus potential fees ($25-$100+).
Why Reclassification Happens
- Actual dimensions exceed declared
- Weight doesn't match documentation
- Commodity doesn't match description
- Special handling needs weren't noted
How to Dispute Reclassification
- Provide photos with measurements visible
- Show scale tickets with weights
- Reference specific NMFC item numbers
- File dispute within carrier's timeframe
Industry-Specific Classification Tips
Different industries face unique freight classification challenges. Here's what to know for common commodities:
Manufacturing & Auto Parts
- Metal parts often qualify for Class 50-70
- Sheet metal and body panels rate higher (150-200)
- Machine tools vary widely by density
- Consider crating for fragile equipment
Electronics & Technology
- Consumer electronics typically Class 85-125
- Servers and networking gear: Class 70-100
- Fragility often increases class regardless of density
- High-value items may need declared value
Furniture & Home Goods
- Assembled furniture: Class 150-300
- Knocked-down (flat pack): Class 85-150
- Mattresses: typically Class 250
- Appliances vary by size and density
Food & Beverage
- Canned goods: Class 55-70
- Bottled beverages: Class 60-70
- Dry goods: Class 70-100
- Temperature-sensitive adds handling class
Frequently Asked Questions
What's the difference between adjacent freight classes?
Adjacent freight classes (like Class 70 vs 77.5) typically differ by about 2-3 lbs/ft³ in density requirements. The cost difference is usually 10-15% between adjacent classes. Moving up one class increases shipping costs, while moving down saves money.
How do I determine my freight class?
Calculate your item's density by dividing its weight by its cubic footage (L × W × H / 1728). Then match the density to the appropriate class range. Also consider handling requirements, stowability, and liability factors that may affect classification.
Can I lower my freight class to save money?
You can potentially lower your freight class by optimizing packaging to increase density. Consolidating items, using smaller boxes, or removing excess packaging can increase density and qualify for a lower class. Always verify the correct class with your carrier to avoid reclassification fees.
What happens if I use the wrong freight class?
Carriers will reclassify your shipment and charge the correct rate plus reclassification fees (typically $25-$100). Repeated errors may result in carrier audits, rate increases, or refused service. It's always better to classify correctly upfront.
Does freight class affect delivery time?
Freight class itself doesn't directly affect transit time. However, higher-class items that require special handling may need more careful loading/unloading, potentially adding time. The main impact is on cost, not speed.
Can the same item have different freight classes?
Yes. How an item is packaged affects its freight class. A product shipped assembled (like furniture) will have a different class than the same product shipped knocked-down or flat-packed due to different densities and handling requirements.
Related Resources
Explore more freight classification tools and guides to help optimize your shipping operations:
Classification Tools
- Complete Classification Guide - In-depth guide to NMFC classification
- Freight FAQ - Answers to common shipping questions
- Shipping Glossary - 400+ logistics terms explained