Freight Class
Also known as: NMFC Class, Shipping Class, Motor Freight Class
Definition
Freight class is a standardized classification system used in LTL shipping to categorize goods and determine pricing. Ranging from 50 to 500, the freight class of your shipment significantly impacts shipping costs—class 500 can cost 3-4x more than class 50.
The 18 Freight Classes
| Class | Examples | $/cwt Range |
|---|---|---|
| 50 | Fits tightly on shrink-wrapped pallets, >50 lbs/ft³ | Lowest |
| 55 | Bricks, cement, mortar | |
| 60 | Car accessories, car parts | |
| 65 | Car accessories and parts, bottled beverages | |
| 70 | Car accessories and parts, food items | |
| 77.5 | Tires, bathroom fixtures | |
| 85 | Crated machinery, cast iron stoves | |
| 92.5 | Computers, monitors, refrigerators | |
| 100 | Boat/car covers, canvas, wine cases | |
| 110 | Cabinets, framed artwork | |
| 125 | Small appliances | |
| 150 | Auto sheet metal parts | |
| 175 | Clothing, couches | |
| 200 | Auto sheet metal parts, aircraft parts | |
| 250 | Mattresses, aircraft parts | |
| 300 | Wood cabinets, tables, chairs | |
| 400 | Deer antlers | |
| 500 | Low density freight, gold dust, ping pong balls | Highest |
How Freight Class Is Determined
The National Motor Freight Classification (NMFC) system uses four criteria:
1. Density (Most Important)
Weight per cubic foot. Higher density = lower class = cheaper.
Formula: Density = Weight ÷ (L × W × H ÷ 1,728)
2. Stowability
How easily freight fits with other cargo. Irregular shapes or hazardous materials score worse.
3. Handling
Special equipment or care needed. Heavy, fragile, or awkward items score worse.
4. Liability
Value and susceptibility to damage/theft. Expensive or easily damaged items score worse.
Finding Your Freight Class
Methods:
- NMFC database - Official classification; requires subscription
- Carrier density calculator - Many carriers provide tools
- Freight broker - They’ll classify for you
- Commodity-based - Some products have fixed classes regardless of density
Density-Based vs. Commodity-Based Classes
| Type | How It Works |
|---|---|
| Density-based | Class determined by actual shipment density |
| Commodity-based | Fixed class assigned to product type (e.g., mattresses = 250) |
Check if your product has a commodity-based class; if not, use density calculation.
Why Getting Class Right Matters
Underclassifying (using lower class than correct):
- Carrier reclassifies and reweighs
- You pay difference plus correction fee ($50-150+)
- Repeated offenses damage carrier relationships
Overclassifying (using higher class):
- You simply overpay
- No penalty, but wasted money
Tips for Lower Freight Costs
- Increase density - Smaller boxes = higher density = lower class
- Stack efficiently - Fill pallets completely
- Use density calculators - Know your class before quoting
- Challenge reclassifications - Sometimes carriers make mistakes
- Consider alternatives - Parcel or FTL might be cheaper