Quick answer: Nm (Numero metrico) is metres of yarn per gram — Nm 28 means 28 metres weigh one gram, and a higher number always means a finer yarn. A cone marked 2/28 is two plies of an Nm 28 single, so its effective count is 28 ÷ 2 = Nm 14, or 1,400 m per 100 g. To go the other way, multiply Nm by 100 for m/100 g or by 1,000 for m/kg.
Every cone in our warehouse carries an Nm figure, because that is how Italian mills label yarn. We have been buying and selling it for two generations — a family business started in Emilia Romagna in the 1970s, now shipping from Dumbrava Roșie in Romania — and reading these counts correctly is the first thing anyone sourcing from Italy has to learn.
What Is Nm?
Nm is the metric count system used across the European textile industry. It tells you how many metres of yarn weigh one gram:
- Nm 28 = 28 metres of single yarn weigh 1 gram (28,000 m/kg)
- The higher the Nm, the finer the yarn
- The lower the Nm, the thicker the yarn
It is an indirect count: length divided by weight. That is the opposite of tex and denier, which measure weight per length and therefore run the other way.
Why Lower Nm Means Thicker Yarn
The definition does the work here. Nm asks how many metres fit into a single gram. A thin, delicate yarn packs a lot of metres into that gram, so its number is high. A thick, heavy yarn uses up the gram in very little length, so its number is low.
| Cone count | Effective Nm | m/100 g | Character |
|---|---|---|---|
| 2/60 | 30 | 3,000 | Very fine — lace, fine gauge machine knitting |
| 2/48 | 24 | 2,400 | Fine — lightweight jersey, multiple ends |
| 2/30 | 15 | 1,500 | Medium-fine |
| 2/28 | 14 | 1,400 | Medium — the workhorse knitwear count |
| 2/16 | 8 | 800 | Thick |
| 2/11 | 5.5 | 550 | Very thick — chunky hand knitting |
One gram of 2/60 gives you 30 metres of thread. The same gram of 2/11 gives only 5.5 metres, because that yarn is far heavier per metre.
Reading Plied Notation Like 2/28
Italian counts are written as plies/Nm — the number of plies first, then the count of each single.
- 2/28 = 2 plies of Nm 28 singles
- 1/15 = a single ply of Nm 15
- 3/48 = 3 plies of Nm 48 singles
To find the effective count of the finished yarn, divide the singles count by the number of plies:
Effective Nm = singles Nm ÷ number of plies
So 2/28 has an effective Nm of 14. This trips people up constantly: a 2/28 cone is not an Nm 28 yarn. The 28 describes each individual strand before twisting, and twisting two of them together halves the metres you get per gram.
Watch for the order, too. Some suppliers write the same yarn as 28/2. If one number is much larger than the other, the large one is almost always the count and the small one the ply.
Converting Nm to Metres per Kilogram
The arithmetic is straightforward:
- m/kg = Nm × 1,000
- m/100 g = Nm × 100
| Yarn | Effective Nm | m/kg | m/100 g |
|---|---|---|---|
| 2/28 | 14 | 14,000 | 1,400 |
| 2/48 | 24 | 24,000 | 2,400 |
| 1/15 | 15 | 15,000 | 1,500 |
| 3/48 | 16 | 16,000 | 1,600 |
This is the conversion that matters commercially. Yarn is priced and shipped by weight but consumed by length, so m/kg is what tells you whether a kilogram will actually cover the run you are planning.
Combining Yarns: The Harmonic Formula
When several yarns are held together — extremely common in machine knitting, where fine cone counts are worked several ends at a time — the resulting count is not the average. It is the reciprocal sum:
1/Nm(result) = 1/Nm₁ + 1/Nm₂ + 1/Nm₃ + …
Example: 2/28 held with 2/48
- Effective Nm of 2/28 = 14
- Effective Nm of 2/48 = 24
- 1/Nm(result) = 1/14 + 1/24 = 38/336
- Nm(result) = 336/38 ≈ 8.84
That is roughly 8,842 m/kg, or 884 m per 100 g.
Why Not a Simple Average?
Because each strand brings its own weight per metre, and weights add while counts do not. A thicker yarn (lower Nm) contributes more grams per metre than a thinner one, so the combined result always sits closer to the thicker yarn's count than a midpoint would suggest. The average of 14 and 24 is 19; the true answer is 8.84 — not merely a different number but a far thicker yarn than averaging implies. Getting this wrong is the most common source of unexpected fabric weight.
Nm, Ne, Tex and Denier
Nm is one of four systems you will meet. Nm and Ne are indirect counts where higher means finer; tex and denier are direct counts where higher means thicker.
- Nm → Ne: Ne = Nm × 0.5905
- Nm → tex: tex = 1000 ÷ Nm
- Nm → denier: denier = 9000 ÷ Nm
If you buy in cotton count, our guide to Ne works through the conversion in both directions, including how a 2/28 metric cone maps onto the Ne 16.5/2 notation.
Where You Will See These Counts
The count is only half of a yarn's identity — the fibre is the other half. Our cones carry both: an Nm figure and a composition code such as 100%WS for cashmere or 100%WV for virgin wool. The yarn is original production from Italian mills, sourced through stock and destock channels, and it keeps the mill's own labelling.
For how counts relate to the hand-knitting weight categories (lace through super bulky), see the yarn weight guide. To look up a specific fibre, try the yarn encyclopedia, or browse the catalogue to see the counts we currently hold.
Try It Yourself
Our yarn calculator does all of this instantly. Enter each yarn as a plied count (2/28), as metres per 100 g (1500), or as a direct Nm (8.5), add as many strands as you are holding together, and it returns the combined Nm along with m/kg, m/100 g, Ne and tex.