How to understand the different yarn thicknesses?

Lace, Fingering, DK? These terms vaguely tell you something but you don't really know what they correspond to? That's what we're going to discover together in this article.

What is the thickness of a thread?

The thickness of a thread is the ratio between its weight and its length. In the textile industry, this ratio is calculated based on a weight of one kilo but in knitting or crochet, it is preferably calculated based on a ball weight of 50g or 100g but the ratio remains the same.

For example, the longer the thread length in a 50g ball, the finer the thread will be.

Let's now see the categories of thread or the standard classification of wool thicknesses.

Categories of thread thickness

The different thread thicknesses are divided into 7 categories numbered from 0 to 6. I will describe all the categories below.

The sample values and needles are given as an indicative mark to find your way afterwards if the wool's thickness is not indicated in the model you have chosen.

Category 0 - Lace

This category of thread includes the finest threads. It is mainly used for lace patterns. The knitted or crocheted work will be fine, light and flexible.

• Type of wool:
• Cobweb
• Lace
• Sample: 32+ stitches
• Needles: <= 2 mm.

Category 1 - Super Fine

This category includes classic sock yarns and wools for babies. The threads in this category remain thin. They allow for light pieces with already good maintenance (of course this depends on the needles, the sample... ;).

• Type of wool:
• Fingering
• Sock
• Baby
• Sample: 28 - 32 stitches
• Needles: 2.25 - 3.25 mm.

Category 2 - Fine

Superior to the Super Fine category, here you will find Sport type threads for finer works but already thicker. Ideal category for accessories like hats and scarves.

• Type of wool:
• Sport
• Sample: 24 - 28 stitches
• Needles: 3.25 - 3.75 mm.

Category 3 - Light

This category of thread includes one of the most commonly used thread thicknesses, the famous DK which in English means "Double Knit" which corresponds to category 3 threads knitted double (2 Fingering = 1 DK).

• Type of wool:
• DK
• Sample: 20 - 24 stitches
• Needles: 3.5 - 4.5 mm.

Category 4 - Medium

This is the ideal thread category for winter sweaters. Stitches aren't too big, but the pieces are warm!

• Type of wool:
• Worsted
• Aran
• Sample: 16 - 20 stitches
• Needles: 4.5 - 5.5 mm.

Category 5 - Bulky

Knitting or crocheting is fast with this thread category but beware the stitches are large.

• Type of wool:
• Bulky
• Sample: 12 - 16 stitches
• Needles: 5.5 - 8 mm.

Category 6 - Super Bulky

Last thread category grouping all the biggest and thickest threads. It's the paradise of giant stitches. The pieces are made quickly but watch out for the weight of the pieces, a sweater knitted with Chunky wool can quickly become heavy!

• Type of wool:
• Super Bulky
• Chunky
• Jumbo
• Sample: <12 stitches
• Needles: 8+ mm.

Recap table

There is a recap table of thread thicknesses that we often see. I am also adding it here. Now that these categories make more sense to you, it will be easier for you to understand this table.