Yarn count
Also searched as: count, yarn number, yarn size, cotton count, Ne, NeC, English count, metric count, Nm, worsted count, direct count, indirect count
Yarn count is a number expressing a yarn's fineness as length per unit mass (indirect systems such as Ne and Nm) or mass per unit length (direct systems such as tex and denier).
In detail
Two families of count coexist. Indirect systems count how many standard lengths weigh a fixed mass, so a higher number means a finer yarn: English cotton count Ne counts 840-yard hanks per pound, metric count Nm counts kilometers per kilogram, and worsted count counts 560-yard hanks per pound. Direct systems, tex and denier, give mass per fixed length, so a higher number means a coarser yarn. Mills, spinners and retailers still quote whichever system their sector grew up with, which is why the system must always be named alongside the number.
The science and numbers
Definitions give the conversions. Ne equals length in yards divided by 840 times mass in pounds; Nm equals length in meters divided by mass in grams. Because tex is grams per 1,000 meters, Nm equals 1,000 divided by tex, and Ne equals about 590.5 divided by tex; Ne is also Nm divided by about 1.693. For worsted count, the 560-yard hank gives tex of roughly 886 divided by the worsted count. Plied yarns in indirect systems combine reciprocally: two singles of count N give a nominal resultant near N divided by 2, whereas in tex the singles values add. ASTM D2260 tabulates conversion factors and equivalent yarn numbers across numbering systems, consistent with ISO 2947.
A practical example
A shirting yarn is described as 30s cotton. In Ne that means thirty 840-yard hanks weigh one pound. Converting gives about 19.7 tex, about 177 denier and about Nm 51. A student comparing it with a knitwear yarn sold as Nm 2/48 should first recognize that the second number is metric and describes two plies of Nm 48 singles, resulting in roughly Nm 24 before twist contraction.
What to distinguish
A bare number such as 40 is meaningless without its system: 40 Ne is a fine cotton yarn, while 40 tex is a much heavier one. Ply notation also differs between trades and regions, so confirm whether a quoted figure is the singles count or the resultant plied count. Count alone does not describe fiber quality, twist, strength or evenness.
Origins and history
Indirect counts grew out of reeling practice: yarn was wound into hanks of a customary length, and a spinner's count recorded how many hanks made up a pound. Different sectors fixed different hank lengths, which is why cotton uses 840 yards and worsted 560 yards. Standardization bodies later framed tex as a common metric replacement and published conversion tables so that traditional counts could be translated rather than abandoned overnight.
Related terms
Sources & further reading
- ASTM: D2260 Standard Tables of Conversion Factors and Equivalent Yarn Numbers
- Textile School: Yarn count conversions, formulas and conversion factors
- A&E Gutermann: Textile unit calculator and numbering systems
- ISO: ISO 1144:2016 Universal system for designating linear density (Tex System)
Technical references reviewed 2026-09-22. Examples are illustrative. Industry organizations and manufacturers describe their own fields; their references are not independent product endorsements. Figures are approximate and depend on the stated test conditions.