Why Ne and Nm are not the same number

Short answer: Both numbers describe how fine a yarn is, but they count in different units. Nm is roughly 1.7 times as high as Ne for the same yarn. Knowing the difference helps you avoid misreading a number when you look at a data sheet or a description.

Two systems, same purpose

Ne comes from the English cotton industry, Nm from the metric system. Both say how many units of length of yarn go into one unit of weight. The higher the number, the thinner the thread in both systems. That is why it is easy to assume the numbers are the same when in fact they are not.

Where Ne comes from

Ne comes from the English cotton industry and is still widely used for cotton and cotton-like yarns. The number says how many lengths of a certain size go into one unit of weight. It is an old system, but it is in use today, and so you often come across it.

Where Nm comes from

Nm belongs to the metric system, which is used across much of the world. Here too the number tells you how much length the yarn has per unit of weight, but the units are metric. Nm is often used for wool and blends. The purpose is the same as with Ne, but the sum is different.

How to convert between them

A yarn of Ne 30 corresponds to roughly Nm 51, because you multiply by 1.693. If you read a data sheet without seeing which unit is stated, you might think the yarn is twice as fine. See Jack and Jones to see how brands present their clothes.

An example with numbers

Take a yarn of Ne 30. Multiply by 1.693 and you get roughly 51 in Nm, and that is the same yarn with a different number. If you do not watch the unit, 51 can look like something quite different from 30. This little sum can save you a misunderstanding.

What it means in the shop

The number is rarely on a product page, but it lies behind the difference between a thin summer fabric and a denser basic fabric. Ask about fabric weight instead, which is easier to compare. See bamboo t-shirts for men and bamboo underpants for men.

Thinner is not always better

A higher number means a thinner thread, but it does not automatically mean a better fabric. Thin threads give a finer look, but not always a stronger one. What is best depends on what the clothes are for and how they should feel. The number is only one of several details.

How to read a data sheet

First check which unit is stated before you compare numbers. If it says Ne, remember the conversion if you want to compare with Nm. If you are unsure, ask. Once you know the difference, a data sheet becomes far easier to understand, and the numbers become usable.

Frequently asked questions

Which number is used most in knitwear?

Ne is most common for cotton and cotton-like yarns, Nm for wool and blends. What is used therefore often depends on what kind of yarn it is.

Does a higher number always mean better quality?

No. It means a thinner thread, and a thinner thread is not always stronger. Quality depends on several things, such as the fibre, the spinning and the knitting.