Make sure that the carpet you choose is the right quality for the situation in which you wish to use it. Consider the following criteria to judge the quality of the carpet.
Construction- Know about the constructions whether it is tufted, woven, knitted or needle punched(more details given under construction)
Density: Consider the density of the carpet. i.e how closely the yarns are together, what ply and weight. This indicates the denseness resilience and weight of the pile. Press your thumb into the pile to see how quickly it recovers, the quicker it does, the denser and more resilient the carpet. Short, dense-fiber carpets are most durable while long strands and big loops may look bulky but they are weight less.
Pile height: The pile height and its character i.e shag, plush, frieze or twist and cut or loop.
Fiber: Know about the fiber and its characteristics. Are they resistant to mildew and stains, do they absorb soil and do they resist abrasion.
Resilience: Consider how resilient the pile is. Consider how quickly it spring back after being walked on and is it comfortable.
Color: Color of the carpet whether it runs or fades.
Style: Select the carpet in relation with the style of your interior setting such as formal, Informal traditional or modern.
Backing: Know about the type of the backing and padding used. Whether it is mildew resistant and it will help the carpet wear better
Installation: Find out whether it is easy to install and needs any pre-preparation.
Maintenance: Know about maintenance and cleaning techniques