Work out yarn count conversion instantly with clear inputs, formula shown and shareable results.
Direct systems state mass per unit length — tex is grams per 1000 metres and denier grams per 9000 metres — so a higher number means a coarser yarn. Indirect systems state length per unit mass, so English cotton count Ne and metric count Nm rise as the yarn gets finer. Tex acts as the common bridge: Ne = 590.5 / tex and Nm = 1000 / tex.
Count conversions
tex = denier / 9 = 590.5 / Ne = 1000 / Nm
Yarn weight
Weight (kg) = tex x length (m) / 1,000,000
One hank of cotton is 840 yards per pound. Converting yards and pounds to metres and grams gives 590.5 grams per 1000 metres for a count of one.
Tex or decitex is the ISO preference and the only sensible choice for mixed-fibre or technical yarns. Ne persists in cotton spinning and denier in filament yarns by convention.