Convert Yorkshire Woollen Count to Tex (NY to tex)

Formula

tex = 1937.71346819 ÷ NY

Derivation from SI units:

• Yorkshire woollen count = number of 256-yard skeins per pound, so tex = 1937.7 ÷ count
• 1 tex = 1 g per 1000 m = 10⁻⁶ kg/m (exact)
• Solving for tex: tex = 1937.71346819 ÷ NY (a higher NY means a lower tex)

Both units are defined exactly, so the factor is exact. Yorkshire Woollen Count definition: Yorkshire woollen count; Tex definition: tex.

Worked examples

1. A reading of 10 NY converts to 193.7713468 tex.
   1937.713468 ÷ 10 = 193.7713468 tex
2. A value of 20 NY is 96.88567341 tex.
   1937.713468 ÷ 20 = 96.88567341 tex

Where it's used

Yorkshire Woollen Count are used for woollen-spun yarns for tweeds and blankets, while tex appear in yarn specifications in metric countries. Both measure yarn count (linear density of yarns and fibres), but one system is the inverse of the other, so a fixed constant is divided by the value.

Yorkshire Woollen Count to other yarn count units

Frequently asked questions

Sources

• ASTM D2260, Standard Tables of Conversion Factors and Equivalent Yarn Numbers Measured in Various Numbering Systems, ASTM International , Woollen count (Yorkshire skeins).
• Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "yard" and "pound".
• ISO 1144, Textiles — Universal system for designating linear density (Tex System), International Organization for Standardization , Tex system.

Last reviewed: 2026-10-15. Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.