You should make use of any and all other details the manufacturer chooses to put on the label. Virtually every detail will tell a smart consumer something significant.
Size is one of those important details. Make sure to go carpet shopping equipped with room measurements, and check the available dimensions of the different carpets. Keep in mind that you may need to get more carpet square-footage than the room's actual size. For instance, if the room is 10-by-10 feet, ordering exactly 100 square feet of 12-foot-wide carpet will result in 8.33-by-12 foot carpet. You'll come up short on the width and have to cut off, seeming it with the excess length [source: Hilton].
Check the label for well-known manufacturer names. These are more likely to be high-quality. It can be difficult at first to recognize differences among carpet manufacturers. However, you can research its reputation of quality and user reviews.
Labels may also list the carpet collection -- a manufacturer's line of similarly styled carpets. If you want matching carpets in various colors for different rooms, you might want to select from the same collection.