What is Denier?

Denier (abbreviated den) is the weight in grams of 9,000 meters of fiber or yarn. A 450-denier yarn weighs 450 g per 9,000 meters (Cotton Incorporated, TRI 1014). Denier is a direct (weight-based) system: the higher the number, the thicker the yarn. In Cotton Incorporated’s classification, denier is the unit used for man-made fibers and yarns. Turkish suppliers write it as denye.

How is denier calculated?

Denier = weight (g) ÷ length (m) × 9,000 (Çukurova University lab sheet). Example: if 250 m of yarn weighs 10 g, the denier is 10 ÷ 250 × 9,000 = 360. The same yarn is 10 ÷ 250 × 1,000 = 40 tex.

Relationship to tex, dtex, Nm and Ne

Tex is the weight in grams of 1,000 m of yarn; denier is that of 9,000 m. So denier = 9 × tex and tex = denier ÷ 9 (TRI 1014, Table 2). Decitex (dtex) is the weight in grams of 10,000 m of yarn; 1 dtex is 1/10 tex. Accordingly, 1 denier is about 1.11 dtex. Conversion to Nm: Nm = 9,000 ÷ denier (TRI 1014; Çukurova lab sheet).

Conversion to Ne: Ne = 5,315 ÷ denier. So 150 denier is about Ne 35.4, and an Ne 30 cotton yarn is about 177 denier (5,315 ÷ 30). For Ne 40 the result is about 133 denier (an example in the Çukurova lab sheet). The coefficients are rounded; with the exact coefficient the figure is 5,314.9 rather than 5,315. Mark a converted value as “approximately” in the specification. For the details of Ne and Nm conversions, see the yarn count conversion guide.

Total denier and denier per filament

Denier is used for the fineness of both a single filament and a whole yarn. A 1.5-denier filament weighs 1.5 g per 9,000 m. If a 450-denier yarn is made of 1.5-denier filaments, it contains 450 ÷ 1.5 = 300 filaments (TRI 1014). Saying “150 denier” does not tell you by itself which is meant; in a specification, write the total denier and the filament count separately.

According to the Fairchild Books Dictionary of Textiles, the term microfiber means a very fine filament or staple fiber: generally fibers of less than 1.0 denier per filament or less than 10 microns in diameter. This definition was cited in a ruling by US Customs and Border Protection (International Trade Today, November 18, 2022).

Which yarns use denier?

According to Cotton Incorporated, denier is used for man-made fibers and yarns, Ne for cotton and cotton-blend yarns, Nm for all yarns in Europe, and tex as the scientific designation for all yarns (TRI 1014, Table 1). ISO 1144:2016 states that the tex system can be applied to all fibers, intermediate products and yarns. A yarn manufacturer (Amann) writes that tights are still classified by denier and that these old designations will most likely continue to be used, to avoid confusing consumers. A yarn supplier (Swicofil), on the other hand, cites dtex as the numbering unit accepted by international bodies for filament and spun yarns in the man-made fiber industry. So the same yarn may be written in different units in a quote; do the conversion with the coefficients above. You can find polyester yarn suppliers in the polyester yarn companies category, and tights and sock manufacturers in the socks and hosiery category.

Counts confused with denier

• Ne and Nm: As denier rises, the yarn gets thicker; as Ne and Nm rise, it gets finer. “40 denier” and “Ne 40” describe completely different yarns: Ne 40 is about 133 denier.
• dtex: A dtex value is 10 times the tex value, while a denier value is 9 times the tex value. Confusing the two causes an error of about 10–11%.
• GSM: Denier is the weight of yarn by length (g per 9,000 m); GSM is the weight of fabric by area (g/m²). They are not the same thing.

Frequently asked questions

How many tex is 1 denier?

1 denier is 1/9 tex, about 0.111 tex (TRI 1014). Conversely, 1 tex is 9 denier. In dtex, 1 denier is about 1.11 dtex.

Does a high denier mean a thick yarn?

Yes. Denier is a direct system: the number rises as the yarn gets coarser, that is, heavier over the same length (TRI 1014). In Ne and Nm it is the other way round: the yarn gets finer as the number rises.

Are total denier and denier per filament the same?

No. Total denier is the weight of 9,000 m of the whole yarn; denier per filament is the weight of a single filament. Divide the total denier by the number of filaments to get the denier per filament: if a 450-denier yarn consists of 300 filaments, it is 1.5 denier per filament (TRI 1014).

How do you convert between denier and Ne?

Denier = 5,315 ÷ Ne and Ne = 5,315 ÷ denier. For example, Ne 30 is about 177 denier; 150 denier is about Ne 35.4.