What Is Freight Class?
Freight class is the standardized classification system used by the National Motor Freight Traffic Association (NMFTA) to price less-than-truckload (LTL) shipments. Every LTL carrier in North America prices off the same 18-class scale — from Class 50 (densest, cheapest) to Class 500 (lightest and bulkiest, most expensive). The class number isn't arbitrary; it's a proxy for how much trailer space your freight occupies per pound of weight it produces.
The single most important input is density: pounds per cubic foot. A 500 lb pallet that's 48"×40"×48" works out to roughly 11.25 lbs/ft³ — that's Class 85. The same 500 lb pallet stacked twice as tall comes in at 5.6 lbs/ft³ — that's Class 150, and the rate goes up sharply. This is why a $0.50 dimensional measurement error can cost you a $200 reclass fee from the carrier. Other factors that can move your class up or down include stowability (irregular shapes), handling (forklift-friendly vs not), and liability (high-value or hazmat).
Use the calculator above to get the class and an instant LTL rate estimate. If your shipment is real and ready to move, call (786) 574-5774 — an ATI freight coordinator will lock in a firm rate from our network of 100+ LTL carriers, usually within 2 minutes.
NMFC Density-to-Class Table
This is the canonical density-only mapping. Most general commodities (no special handling, stowability, or liability concerns) classify directly by density. For commodities with a specific NMFC item number, that item's published class always wins.
| Density (lbs / ft³) | Freight Class |
|---|---|
| 50+ | 50 |
| 35 – 50 | 55 |
| 30 – 35 | 60 |
| 22.5 – 30 | 65 |
| 15 – 22.5 | 70 |
| 13.5 – 15 | 77.5 |
| 12 – 13.5 | 85 |
| 10.5 – 12 | 92.5 |
| 9 – 10.5 | 100 |
| 8 – 9 | 110 |
| 7 – 8 | 125 |
| 6 – 7 | 150 |
| 5 – 6 | 175 |
| 4 – 5 | 200 |
| 3 – 4 | 250 |
| 2 – 3 | 300 |
| 1 – 2 | 400 |
| < 1 | 500 |
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Call (786) 574-5774 or email rates@ship-ati.comWhen Do You Need to Declare Freight Class?
You declare a freight class on the bill of lading (BOL) for every LTL shipment. The carrier weighs and measures the shipment at the terminal — if your declared class is wrong (usually because of inaccurate dimensions or weight), the carrier will reclassify the shipment and bill you a reweigh/reinspection fee plus the difference in class rate. Getting it right up front saves money and disputes.
Density vs. NMFC Item Number
Most general commodities use the density-based class above. But some commodities have a specific NMFC item number that overrides density — these are usually high-value, hazmat, or irregular-shape items (e.g. mattresses, automobile parts, machinery). If you're not sure whether your commodity has a fixed NMFC class, call us — getting this wrong is the #1 source of reclass fees.