Yarn Count Converter (Tex, Denier, Ne, Nm, Worsted)

How it works

tex = g per 1,000 m = grams ÷ metres × 1,000; dtex = 10 × tex; denier = 9 × tex; ktex = tex ÷ 1,000; indirect counts: tex = K ÷ count, with K = 453,592.37 ÷ (yards per hank × 0.9144) — Ne (840 yd) 590.54, worsted (560 yd) 885.81, linen lea (300 yd) 1,653.5, Yorkshire woollen (256 yd) 1,937.7, American run (1,600 yd) 310.03, yd/lb 496,055; Nm = 1,000 ÷ tex; Nf = 500 ÷ tex; jute tex = 34.448 × lb per spyndle; plied resultant tex = sum of the plies’ tex ÷ (1 − twist contraction); denier per filament = denier ÷ filaments

Yarn thickness cannot be measured with callipers — a spun yarn is fuzzy and compressible — so the textile trade expresses it as linear density: weight per length, or length per weight. Tex (grams per kilometre), decitex, kilotex and denier (grams per 9,000 metres) are direct systems where a bigger number means a heavier yarn, used for filament, industrial yarns and slivers; jute’s pounds per spyndle is direct too. English cotton count (hanks of 840 yards per pound), metric count, worsted, woollen and linen lea counts are indirect systems where a bigger number means a finer yarn, still universal in spinning and weaving. Every one converts through tex with a constant derived from the exact yard and pound. If you have a yarn but no label, choose the weighed-sample mode: reel off a known length, weigh it (in grams, milligrams or grains) and the count follows; add the commercial moisture regain if you oven-dried it. Plied yarns need care: a 30/2 cotton is two singles of Ne 30 twisted together, giving the weight of a Ne 15, and plies of different counts simply add their tex — plying twist also shortens the yarn slightly, which the contraction option allows for. With the filament count you get denier per filament, the figure that defines microfibres. Knowing the tex lets you weigh a cone to find its length, estimate diameter and choose needle and reed sizes.

Worked example

Ne 30 single cotton is 590.54 ÷ 30 = 19.68 tex — 177 denier, Nm 50.8, 25,200 yards per pound — about 0.166 mm in diameter, and 1,000 m of it weighs 19.7 g. Plied as 30/2 it becomes 39.4 tex, equivalent to a Ne 15. A Ne 30 and a Ne 40 twisted together are 19.68 + 14.76 = 34.45 tex, a resultant Ne 17.1. A 100 m skein weighing 1.97 g is 19.7 tex — the same Ne 30. A 150-denier polyester with 48 filaments is 3.1 denier per filament, and a 1 kg cone of 150 denier holds 60,000 m.

Frequently asked questions