Textile Unit Converter

About the textile unit converter

Yarn is sold by a count, and the count systems fall into two families. Direct systems — tex, decitex and denier — measure mass per fixed length, so a bigger number means a thicker yarn. Indirect systems — Nm, Ne and the worsted and linen counts — measure length per fixed mass, so a bigger number means a finer yarn.

Everything here is converted through tex, the SI-friendly unit of grams per 1,000 metres. Tex is the honest backbone of the list: 1 tex is 1 g/km, 1 decitex is 0.1 tex, and 1 denier is 1/9 tex.

Conversion factors

How to convert textile counts

Every conversion goes through tex. To change a denier into a cotton count, first find tex = denier ÷ 9, then Ne = 590.54 ÷ tex. For example 150 denier is 16.67 tex, which is 590.54 ÷ 16.67 = 35.4 Ne.

Worked examples

• 150 denier polyester is 16.67 tex and 166.7 decitex.
• 20 Ne cotton is 590.54 ÷ 20 = 29.5 tex, a common knitting yarn weight.
• 1/30 Nm wool is 33.3 tex; plied 2/30 Nm doubles the mass per length, so treat it as 2/30 = 15 Nm, or 66.7 tex.
• Fine machine embroidery thread at 40 weight is roughly 27 tex.

Direct and indirect counts run in opposite directions

Textile numbering systems fall into two families, and the difference is the single most common source of mistakes. In a direct system the number measures mass per unit length, so a bigger number means a thicker yarn: tex (grams per 1,000 m), decitex (grams per 10,000 m) and denier (grams per 9,000 m) all work this way.

In an indirect system the number measures length per unit mass, so a bigger number means a finer yarn: the cotton count Ne (840-yard hanks per pound) and the metric count Nm (1,000 m per kilogram) both work this way. Doubling an indirect count halves the yarn's mass per metre.

Cotton count and worsted count share a name and not a unit. NeC is based on 840-yard hanks of cotton; NeW uses 560-yard hanks of worsted yarn, so the same yarn has a worsted count about 1.5 times its cotton count. A supplier quoting "30s" without naming the system means nothing precise, and a specification that mixes the two can be wrong by a third.

Plied yarns are written as a count followed by the number of plies — 2/60s means two plies of 60-count yarn — and the resulting linear density is not simply double the single yarn. This converter handles single yarns; for plied structures, convert each component and add the masses.

Frequently asked questions

Common mistakes to avoid

• Forgetting the inverse relationship. Halving a direct count like tex doubles an indirect count like Nm.
• Ignoring ply when converting. Always state the resultant count, not just the single yarn.
• Comparing counts across systems. 20 Ne, 20 Nm and 20 denier are three very different yarns.
• Mixing count with fabric weight. GSM measures fabric, not yarn; use it in the weight and area converters instead.

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