Why Freight Class Matters
Freight Class is the single biggest factor in your LTL shipping rate. Getting it wrong can result in a carrier rebill — sometimes 2-3x your original quote. Every LTL shipper needs to understand this system.
The 18 Freight Classes
The National Motor Freight Traffic Association (NMFTA) defines 18 classes from 50 (cheapest) to 500 (most expensive):
| Class | Density Range | Type of Freight |
|---|---|---|
| 50 | 50+ lbs/ft³ | Clean freight: steel, heavy machinery, cement |
| 55 | 35-50 | Bricks, hardwood flooring, mortar |
| 60 | 30-35 | Car accessories, bottled beverages |
| 65 | 22.5-30 | Car parts, bottled drinks, books |
| 70 | 15-22.5 | Food items, car parts, machinery parts |
| 77.5 | 13.5-15 | Tires, bathroom fixtures |
| 85 | 12-13.5 | Crated machinery, cast iron stoves |
| 92.5 | 10.5-12 | Computers, monitors, refrigerators |
| 100 | 9-10.5 | Boat covers, canvas, wine cases |
| 110 | 8-9 | Cabinets, framed artwork, table saws |
| 125 | 7-8 | Small appliances, toolboxes |
| 150 | 6-7 | Auto sheet metal, bookcases |
| 175 | 5-6 | Clothing, couches, stuffed furniture |
| 200 | 4-5 | Auto parts, aluminum tables, mattresses |
| 250 | 3-4 | Bamboo furniture, mattresses, plasma TVs |
| 300 | 2-3 | Wood cabinets, tables, chairs (setup) |
| 400 | 1-2 | Deer antlers, light fixtures |
| 500 | <1 | Bags of gold dust, ping pong balls |
How to Determine Your Class
Two methods:
- By NMFC code — Every product has an NMFC code that maps to a class. Use our NMFC Lookup Tool to search.
- By density — Calculate: Weight (lbs) ÷ Cubic feet. Then match to the density range above.
Cubic feet = (Length × Width × Height in inches) ÷ 1,728
What Happens If You Get It Wrong?
Carriers inspect and weigh shipments. If your declared class doesn't match the actual freight, they will rebill you at the correct class — plus an inspection fee ($50-$100). This can double your shipping cost.
Always verify your freight class before booking. When in doubt, ask your carrier or use a density calculator.
NMFC codes and freight classes shown here are a reference estimate — the carrier makes the final classification based on the actual commodity, density, packaging, and NMFC rules. For an accurate LTL quote, prepare your origin/destination ZIP, commodity, weight & dimensions, and pallet count.
Get LTL Quote → NMFC & Class Lookup Address Checker