We discussed some of the carpet label specifications that can help you determine durability, such as twist and density. However, because these are variables that also depend on the fiber type, comparing different specifications across several different carpet samples can be dizzying.
To make comparison shopping exponentially easier, there are some standardized durability tests. A number on the carpet label could refer to such a test.
Both the Carpet and Rug Institute (CRI) and Consumer Reports endorse the Home Depot durability rating system, which they call the Performance Appearance Rating (PAR). Home Depot uses a walk test that's supposed to simulate what the carpet will look like after a year of normal traffic by a family of four. When you're inspecting a label, look for a score from 1 to 5. A high score of 4 or 5 will quickly tell you that a carpet has good durability [source: Home Depot]. Other major retailers use similar durability tests. Shaw Floors, for example, uses its own performance rating, which also ranges from 1 to 5.
These ratings systems somewhat oversimplify the issue of durability. How your carpet will look also depends on maintenance and traffic. Though you shouldn't necessarily make your decision based solely on such performance ratings, considering them in conjunction with other specifications like twist and density will help in your decision.