From weight, to density, twist, and fiber construction, there is a lot to consider when purchasing carpet.

Face Weight

Carpet face weight is the weight of the carpet pile per square yard of carpet, measured in ounces. Unfortunately, face weight has been so heavily marketed that many consumers are given the impression that it is the best way to determine a carpet’s durability.

It can be easy to believe that a higher face weight represents a more durable carpet, but this is not always the case, because several things influence a carpet’s weight.

Carpet Density

Carpet density refers to how close together the fibers are tufted (stitched) into the carpet backing. It is calculated using a specific formula. When comparing carpets that have different densities, but are equivalent in all other ways (same fiber type, style, etc.) then a higher density value indicates a more durable carpet.

Fiber Twist

The twist of the fiber is often one of the most overlooked aspects of a carpet, and yet it is one of the best indicators of carpet quality. The fiber twist refers to the number of times that the strands of fiber are twisted together, as measured to within a one-inch length of the fiber. The result is known as a carpet’s twist number; it is sometimes referred to as turns-per-inch (TPI).

This is easy to calculate yourself. Measure a one-inch length of the carpet fiber, and count how many turns you see in it. If the fiber is shorter than one inch, measure a half-inch and then double the number of twists you count, to get the twist number.

Type of Fiber

The type of fiber the carpet is made of is a huge factor in the carpet’s quality. Different fibers have different characteristics, and some fiber types work better in certain situations than others.

Common synthetic carpet fibers include nylon, polyester, olefin (polypropylene) and triexta. Natural carpet fibers such as wool and sisal are used less often, but still, play a role in the carpet industry.

Check the label, handle the carpet and ask the salesperson about these signs of quality:

  • At least a 34- to 40-oz. face weight.This is the number of ounces of fiber per square yard. The range is generally from 20 to 80, and the higher the number, the heavier and more resilient the carpet.
  • A tuft twist of 5 or higher.Twist is the number of times the tufts are twisted together in a 1-in. length. The higher the number, the more durable the carpet.
  • A density rating of 2,000 or more.Density is determined by the thickness of the fibers and how tightly packed they are. The thicker and heavier they are, the better quality the carpet and the less susceptible to crushing. Bend the carpet sample backward (Photo). If you can see the backing easily, it’s a low-density (lower quality) carpet.
  • Is it BCF or staple fiber construction?Carpet fibers can be either Bulked Continuous Filament (BCF) or staple. Staple fibers shed more than BCF fibers. This doesn’t affect the long-term quality of the carpet, but it does mean you’ll have to vacuum more often until the initial shedding stops (which can take up to a year), and it can also be an issue for allergy sufferers.