Choosing carpet, whether you're building custom or updating a home, can be intimidating. Not only is it a huge financial investment, but replacing it is difficult enough that you want to be able to live with your choice for a LONG time. The two biggest points, other than price, to consider are Fiber and Style.
The fiber you choose will affect durability, resilience, and maintenance. About 99% of all carpets in the US are made from synthetic materials: nylon, polypropylene (olefin), acrylic, polyester, wool, or cotton. Strong and soft at the same time, nylon is the most popular choice, especially if you want your carpet to last 10 years or more. Polyester is also resilient and soft, but harder to clean and a little less durable. If you have low traffic areas or live without children or pets, you'll appreciate the softness beneath your feet. Learn more about the properties of different carpet fibers here.
Carpet style is another factor in your decision making. The most popular styles are:
Plush works well in formal areas. Because it shows footprints and vacuum marks, you won't want it in high-traffic areas like living rooms, play rooms, and children's rooms. You can expect basic-grade plush carpet to last about 5 years.
Textured carpet usually has more than one color and different lengths of tufts. It's appearance is great for hiding dirt, footprints, and vacuum marks since it appears two-toned. This is a great choice for high-traffic areas and active rooms.
Frieze is expensive, but durable. It's nubby texture, thanks to it's twisted tufts, make it perfect for covering footprints and other wear and tear. Though it's more pricey than other options, it can last up to 20 years when well maintained.
Berber, also called Looped, comes in a variety of loop sizes. It's easy to clean, but not a great choice with small children and pets, because the loops snag easily and are hard to repair.