Yarn count is a number that expresses how fine or coarse a yarn is, by relating its length to its weight. The confusion around it comes from the fact that the textile industry never settled on one system: some count systems get larger as the yarn gets finer, and others get larger as it gets coarser. Read the number without knowing the system, and you can order the opposite of what you meant.
What does yarn count actually measure?
Every count system answers one of two questions: how much length do you get per unit of weight?, or how much does a fixed length weigh? That single choice splits every system in the world into two families.
- Indirect systems measure length per unit weight. A higher number means more length per kilogram — so a higher number is a finer yarn. Ne and Nm are indirect.
- Direct systems measure weight per unit length. A higher number means the fixed length weighs more — so a higher number is a coarser yarn. Tex and denier are direct.
Get that distinction right and everything else is arithmetic. Get it wrong and a "40" means something entirely different depending on which system the mill quoted.
The four systems you will actually meet
| System | Type | Definition | Higher number = |
|---|---|---|---|
| Ne (English cotton count) | Indirect | Number of 840-yard hanks in one pound | Finer |
| Nm (metric count) | Indirect | Length in kilometres of one kilogram (metres per gram) | Finer |
| Tex | Direct | Weight in grams of 1,000 metres | Coarser |
| Denier | Direct | Weight in grams of 9,000 metres | Coarser |
Ne is the common language for cotton and cotton-blend spun yarns, especially across South Asia. Nm turns up on worsted, woollen and many blended yarns. Tex is the SI unit and the one most standards bodies prefer. Denier survives mainly for filament and man-made yarns — the "denier" of a pair of tights is the same unit.
How to convert between them
Only a handful of constants are needed. Keep this box; it settles most yarn conversations before they start.
The conversions worth memorising
Tex = 590.5 ÷ Ne • Ne = 590.5 ÷ Tex
Tex = 1000 ÷ Nm • Nm = 1000 ÷ Tex
Nm = 1.693 × Ne • Denier = 9 × Tex • dtex = 10 × Tex
A worked example: a 30s Ne cotton yarn. Its Tex is 590.5 ÷ 30 = 19.7 tex. Its metric count is 1000 ÷ 19.7 = Nm 50.8 (or simply 1.693 × 30). As denier it would be 9 × 19.7 = 177 denier, though denier is rarely used for cotton. The table below gives the common counts at a glance.
| Ne | Tex | Nm | Denier | Typical use |
|---|---|---|---|---|
| 6 | 98.4 | 10.2 | 886 | Terry, heavy denim, coarse jersey |
| 10 | 59.1 | 16.9 | 532 | Denim, canvas, heavy knits |
| 20 | 29.5 | 33.9 | 266 | Mid-weight jersey, bottomweights |
| 30 | 19.7 | 50.8 | 177 | Single jersey, poplin, shirting |
| 40 | 14.8 | 67.7 | 133 | Fine jersey, fine shirting |
| 60 | 9.8 | 101.6 | 89 | Fine combed shirting, voile |
What about ply — 2/40s, 40/2 and the rest?
A count on its own describes a single yarn. When two or more singles are twisted together, the notation records both the singles count and the number of strands. 2/40s Ne (also written 40/2) means two 40s singles plied together. Because you now have twice the weight for the same length, the resultant count is roughly half — around 20s Ne — even though the yarn is built from 40s singles.
In the direct systems this is simpler: a two-ply of 15 tex singles is about 30 tex resultant, before a small allowance for the contraction that plying twist adds. When you specify a plied yarn, always state both numbers — "2/40s" is unambiguous; "40s ply" is not.
Count is necessary but not sufficient
Two yarns of identical count can behave nothing alike, because count says nothing about the rest of the specification:
- Twist — turns per inch or metre, and direction (S or Z). More twist means a stronger, harder, leaner yarn; less twist means a softer, fuller, more lustrous one.
- Fibre and preparation — combed versus carded cotton at the same count differ in evenness, strength and pilling. A 30s combed and a 30s carded are not interchangeable.
- Spinning system — ring-spun, open-end (rotor) and vortex yarns of the same count have different strength, hairiness and hand.
- Blend ratio — a 30s "PC" could be 65/35 or 52/48 polyester- cotton, and the fabric will dye and wear differently.
A count is the headline of a yarn specification, not the whole of it. The evenness, strength and pilling behaviour that decide whether a yarn is right are settled by twist, fibre, preparation and spinning system — not by the count alone.
How to specify count so nothing is lost
When you send a yarn enquiry, state the count with its system and the construction in one line: for example, "30s Ne combed cotton, ring-spun, single, for single jersey". That tells a mill exactly what to quote and removes the most common source of mismatch — a supplier assuming Nm where you meant Ne, or carded where you meant combed. If a shade or a downstream fabric has already been approved, name it; the count that knitted cleanly last season is the safest starting point for the next.
This is precisely the groundwork we do on every yarn programme — pinning the count, construction and tolerance in writing before an order is confirmed, so the second shipment is measured against the first rather than against a fresh conversation.
Tell us the count and construction.
Send the count with its system, the fibre and the end use. We will come back with the mills genuinely able to hold it, and an honest view of price and lead time.