Convert Yorkshire Woollen Count to Kilotex (NY to ktex)

Formula

ktex = 1.93771346819 ÷ NY

Derivation from SI units:

• Yorkshire woollen count = number of 256-yard skeins per pound, so tex = 1937.7 ÷ count
• 1 ktex = 1 g per metre = 1000 tex = 10⁻³ kg/m (exact)
• Solving for ktex: ktex = 1.93771346819 ÷ NY (a higher NY means a lower ktex)

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

Worked examples

1. A reading of 10 NY converts to 0.1937713468 ktex.
   1.937713468 ÷ 10 = 0.1937713468 ktex
2. A value of 20 NY is 0.09688567341 ktex.
   1.937713468 ÷ 20 = 0.09688567341 ktex

Where it's used

Yorkshire Woollen Count are used for woollen-spun yarns for tweeds and blankets, while kilotex appear in card and draw-frame sliver (about 3–5 ktex). 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.