Convert Kilograms per Metre to Worsted Count (kg/m to Nw)

Formula

Nw = 0.0008858118711724 ÷ kg/m

Derivation from SI units:

• The coherent SI unit of linear density: mass in kilograms per metre of length.
• Nw = number of 560-yard hanks per pound, so tex = 885.8119 ÷ Nw
• Solving for Nw: Nw = 0.0008858118711724 ÷ kg/m (a higher kg/m means a lower Nw)

Both units are defined exactly, so the factor is exact. Kilogram per Metre definition: kilogram per metre; Worsted Count definition: worsted count.

Worked examples

1. A reading of 0.00001 kg/m converts to 88.58118712 Nw.
   0.0008858118712 ÷ 0.00001 = 88.58118712 Nw
2. A value of 0.0001 kg/m is 8.858118712 Nw.
   0.0008858118712 ÷ 0.0001 = 8.858118712 Nw

Where it's used

Kilograms per Metre are used for ropes, cables and heavy tows, while worsted count appear in worsted wool and acrylic yarns. 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.

Kilogram per Metre to other yarn count units

Frequently asked questions

Sources

• The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures .
• ASTM D2260, Standard Tables of Conversion Factors and Equivalent Yarn Numbers Measured in Various Numbering Systems, ASTM International , Worsted count.
• 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".

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