All truck types fall into one in eight classes as identified by the US government's Gross Vehicle Weighting Rating (GVWR). The GVWR, however, is based on the truck's weight when fully loaded. That means including the passengers, cargo, etc. From small trucks to large tractor trailers, trucks are classifed into three major categories down to eight different classes.

Light Duty Trucks (trucks for personal use)
- Majority of personal-use cars fall into Class 1. Commercial trucks like ambulances, small delivery trucks and vans also fall in this category. No special driver's license is needed when driving light duty trucks.
Class 1 Light Duty - Weight: 6,000 lb or less (i.e Toyota Tacoma, Dodge Dakota, GMC Canyon)
Class 2 Light Duty - Weight: 6,001 to 10,000 lb. (i.e Dodge Ram 1500 and Ford F-150)
Class 3 Light Duty - Weight: 10,000 to 14,000 lb. (i.e Ford F-350, GMC Sierra 3500)

Medium Duty Trucks (commercial vehicles that are not available for purchase by the general public)
Class 4 Medium Duty - Weight: 14,001 to 16,000 lb. (Ford F-450 trucks)
Class 5 Medium Duty - Weight: 16,001 to 19,500 lb. (i.e International TerraStar)
Class 6 Heavy Duty - Weight: 19,501 to 26,000 lb. (i.e GMC Topkick C6500)

Heavy Duty Trucks: (semis, tour buses, tractor trailers fall in this category)Class 7 Heavy Duty - Weight: 26,001 to 33,000 lb. (i.e GMC 7500)
Class 8 Heavy Duty - Weight: 33,001+ lb. (include all tractor trailer trucks)