One broker says "75 denier", another says "30s", and both have to go into the same column of your costing sheet. Every weight and cost formula runs on denier, so turning a count into denier is everyday work in a weaving unit. Here is the difference between the two systems, the formulas and the usual mistakes.
Denier: weight per length
Denier = the weight in grams of 9,000 metres of yarn. If 9,000 m weighs 75 g, it is 75 denier. This is a direct system: the higher the denier, the thicker and heavier the yarn. Polyester and nylon filament yarns are sold by denier. Tex (grams per 1,000 m) and dtex (grams per 10,000 m) belong to the same family.
Count (Ne): length per weight
English cotton count (Ne) is the number of 840-yard hanks in one pound of yarn. It is an indirect system: the higher the count, the finer the yarn, so 40s is finer than 30s. Cotton, spun viscose and blends are usually sold by count. The metric count Nm is kilometres of yarn per kilogram.
Nm = 9000 ÷ denier
tex = denier ÷ 9
dtex = denier × 10 ÷ 9
Denier per filament = denier ÷ filaments
Where does 5315 come from? 1 pound = 453.6 g and 840 yards = 768.1 m. Scale that to 9,000 m and you get 5,314.9 — the trade rounds it to 5315. Use the same number both ways and your figures will always match.
Example
- 150 denier weft → Ne = 5315 ÷ 150 = 35.43, Nm = 9000 ÷ 150 = 60, tex = 16.67, dtex = 166.7
- 30s viscose → denier = 5315 ÷ 30 = 177.2
- 40s → 132.9 denier, 60s → 88.6 denier
Swap a 150 denier weft for 30s (177.2 denier) at 50 picks and 65.5 inches panna, and the weft goes from 5.46 to 6.45 kg per 100 m — about 1 kg more on every 100 metres. In the costing that shows up straight away in rupees.
Conversion table
| Denier | Ne | Nm | tex | dtex |
|---|---|---|---|---|
| 50 | 106.3 | 180 | 5.56 | 55.6 |
| 60 | 88.6 | 150 | 6.67 | 66.7 |
| 75 | 70.9 | 120 | 8.33 | 83.3 |
| 100 | 53.2 | 90 | 11.11 | 111.1 |
| 150 | 35.4 | 60 | 16.67 | 166.7 |
| 300 | 17.7 | 30 | 33.33 | 333.3 |
For any other value, use the Yarn Count Converter — enter one unit and the other four appear, with the formula step by step.
What does 75/36 mean?
Filament yarn is often labelled with two numbers: 75/36 means a 75 denier yarn made of 36 filaments. One filament = 75 ÷ 36 = 2.08 denier. A 75/72 yarn still weighs 75 denier, but its filaments are finer (1.04 denier), so the cloth feels softer. For weight and costing only the first number (denier) matters; the filament count changes the handle and look.
On spun yarn, "2/40s" is a different notation: two 40s yarns twisted together, with a resultant of roughly 20s (about 266 denier). Don't read it as 2 ÷ 40 — confirm the resultant count with your supplier.
Common mistakes
- Getting the direction wrong. Higher denier = thicker; higher count = finer. When someone says "60", ask: denier or count?
- Reading Nm as Ne. Nm 60 and Ne 60 are different yarns — Nm 60 is 150 denier, Ne 60 is 88.6 denier.
- Adding the filaments to the denier. A 75/36 yarn weighs 75 denier, not 111.
- Counting ends wrong. The right denier with the wrong number of ends still gives the wrong weight — check it with ends from reed and panna.
In Loomiro
In the free Fabric Costing calculator you can choose Denier or Count (Ne) for every warp and weft; enter a count and the denier is shown for you. In the Loomiro app's Costing module, picking a quality fills in its reed, picks, panna, ends, denier and the last purchase rate of its yarn — with warp and weft kg, weight per 100 m and a full cost-per-metre breakdown. Fill the quality master in once and you never convert by hand again.
Need a quick conversion? The Yarn Count Converter works on a phone too, and you can send the result on WhatsApp.