AC stands for Abrasion Class and is a wear rating that has been standardized by NALFA (North American Laminate Flooring Association). The AC rating measure the abrasion resistance of the floor which determines how well the floor will withstand day to day wear. The AC rating generally ranges from 1 to 5. AC 3 is the industry standard for everyday residential use. AC 4 and AC 5 are considered commercial for heavier traffic areas.