Universal Yarn Count Converter

The formula

This is the expression the tool evaluates. Every term is named underneath, with the unit it must be supplied in.

How the result is derived

Step by step, from the values you type to the figure on screen.

1. The chosen system and value are converted into tex, which is grams per 1000 metres and the SI reference for linear density.
2. A non-positive or non-finite tex stops the conversion rather than propagating nonsense into six other systems.
3. Every other system is then generated from that single tex value, so all seven outputs are guaranteed to describe the same yarn.
4. The constants are fixed definitions, not measurements: 590.5 comes from 840 yard hanks per pound, 885.8 from 560 yard worsted hanks per pound, and 9 from 9000 metres per gram of denier.

What each input means

Where to read each value on the floor, the unit it must be in, and the range the tool accepts.

What the tool returns

The headline figure and every supporting value it is built from.

Worked example

Substituting

A 40s cotton yarn is a 60s worsted, a 133 denier and a 14.76 tex. All four describe the identical yarn — only the reference length and the direction of the scale change.

How to use it

1. Work through the input groups in order — Known Count. The defaults are a realistic case, so you can change one value at a time and watch what moves.
2. There is no calculate button. Every figure recalculates as you type or drag, which is what makes this usable for a what-if sweep rather than a single answer.
3. Read Linear Density in the dark results panel — that is the headline figure, expressed in tex.
4. Check the supporting rows underneath (English Cotton, Metric, Denier, Decitex, Worsted and Jute) before acting on the headline — they are where an implausible input usually shows itself first.
5. Reset to defaults returns every field to the reference case, which is the quickest way to check whether a surprising result came from the tool or from an input you had changed earlier.

Where this is used

• Reading a supplier quotation written in a system your mill does not use, without a conversion error becoming a purchase error.
• Filament and staple in one specification — filament is quoted in denier or dtex, staple yarn in Ne or Nm, and blends have to be reconciled.
• Technical and regional specifications: worsted for wool, jute for packaging and geotextiles, tex wherever an ISO test method is being quoted.
• Cost comparison — yarn price per kilogram is only comparable once counts are on a common basis.

Reading the result

Typical bands and what each one is telling you.

Assumptions and limits

• Indirect systems (Ne, Nm, worsted) rise as the yarn gets finer; direct systems (tex, denier, jute) rise as it gets coarser. Always state the system when quoting a count.
• Every input is bounded to the range normal practice occupies (Counting System Ne — English cotton (indirect) · Nm — Metric (indirect) · Tex — g per 1000 m (direct) · Dtex — g per 10000 m (direct) · Denier — g per 9000 m (direct) · Worsted — 560 yd hanks per lb · Jute — lb per 14400 yd spyndle and Count Value 0.0001 to 100000, and so on for the rest). Those bounds are guard rails against typing errors, not a claim that the formula fails one unit outside them.
• The calculation is deterministic: the same inputs always give the same result. It carries no allowance for machine condition, operator skill, ambient conditions or lot-to-lot material variation unless an input above explicitly represents one.
• Nothing is sent anywhere. The maths runs in your browser, so the numbers you type never leave the page.

Standards and further reading

• ISO 1144 — the tex system for linear density, the reference every other system is defined against here.
• ISO 2060 / ASTM D1907 — determination of yarn linear density by the skein method.
• ASTM D2260 — conversion tables for yarn number, the printed ancestor of this calculator.

Questions people ask