Carpet face weight refers to the weight of the fiber found one square yard of carpet. the standard is measured in ounces.
Carpet density refers to how closely together the fibers are tufted into the carpet backing.
How to Calculate Carpet Density
Carpet density is calculated using the following formula
Carpet face weight multiplied by 36
divided by carpet pile height
equals density, measured in ounces per cubic yard
The pile height is the length of the carpet fibers from their end tips to the point where they reach the carpet backing. In the above formula, pile height should be represented as a fraction of an inch, reflected in decimal format. For example, a pile height of one-half of an inch would be represented as 0.5, while a pile height of a one-quarter of an inch would be 0.25, and so on
The number that results from the above density calculation will be a four-digit number. For example, a carpet with a 50-ounce face weight and a pile height of half of an inch would have a density of 3600 ounces per cubic yard (50 x 36 / 0.5 = 3600).
Judging Carpet Quality
Don’t use one factor alone as an indicator of a carpet’s overall quality. All factors (density, face weight, twist, fiber type, etc.) all work together in a carpet to determine how the carpet will look and perform overall. Each of these factors must all be taken into consideration when making a decision on the appropriate carpet for your home.
However, all other things being equal, the higher the carpet density, the more durable the carpet will be, and the more pleasing it will be underfoot. Just as lawn of turf grass is more luxuriant if the grasses are thick underfoot, a carpet with higher pile density will feel plusher and will hold up better underwear.
Minimum Density Values
For optimal performance in normal household conditions, a density value of 3000 or higher is ideal. According to the Carpet and Rug Institute, extra heavy traffic conditions (such as are found in heavy commercial use) require a minimum density of 5000.