Yarn weights explained: the complete chart (0 to 7)

Yarn weight is the thickness of a strand of yarn, graded by the Craft Yarn Council on a standard scale from 0 (lace, the finest) to 7 (jumbo, the thickest). The weight determines your gauge, which needle size to use, and how the finished fabric will feel, so matching the weight a pattern calls for is essential. This chart shows every standard weight side by side. The sections below explain each one and how to identify the weight of an unlabelled yarn.

Yarn weight chart (at a glance)

#	Category name	Also called	Knit gauge* (sts / 4 in)	Recommended needle (metric)	Recommended needle (US)
0	Lace	Fingering, 10-count crochet thread	33 to 40** sts	1.5 to 2.25 mm	000 to 1
1	Super Fine	Sock, Fingering, Baby	27 to 32 sts	2.25 to 3.25 mm	1 to 3
2	Fine	Sport, Baby	23 to 26 sts	3.25 to 3.75 mm	3 to 5
3	Light	DK, Light Worsted	21 to 24 sts	3.75 to 4.5 mm	5 to 7
4	Medium	Worsted, Afghan, Aran	16 to 20 sts	4.5 to 5.5 mm	7 to 9
5	Bulky	Chunky, Craft, Rug	12 to 15 sts	5.5 to 8 mm	9 to 11
6	Super Bulky	Super Bulky, Roving	7 to 11 sts	8 to 12.75 mm	11 to 17
7	Jumbo	Jumbo, Roving	6 sts and fewer	12.75 mm and larger	17 and larger

(*) Stockinette stitch, the most commonly used gauge. Guidelines only. Always follow the gauge stated in your pattern. ** Lace is usually knitted on larger needles to create openwork, so its gauge range is hard to pin down.

Source: Craft Yarn Council Standard Yarn Weight System.

What each yarn weight is best for

0 (lace). The finest yarn, used for delicate shawls and openwork. Often knitted on larger needles than its thickness suggests, to create the holes in lace.

1 (super fine, fingering or sock). Thin and hard-wearing. The standard for socks, lightweight shawls and fine baby garments. (Fingering weight yarn →)

2 (fine, sport). A step up from fingering. Light sweaters, baby clothes and accessories with good drape.

3 (light, DK). "Double knitting." One of the most versatile weights: sweaters, hats and amigurumi. Popular in Europe. (DK weight yarn →)

4 (medium, worsted or aran). One of the most common weights (especially in North America) and an easy choice for beginners. Thick enough to knit up quickly, thin enough for most garments. (Worsted weight yarn →)

5 (bulky, chunky). Thick and fast. Warm sweaters, scarves and winter hats that can be knitted in an evening.

6 (super bulky). Very thick. Chunky blankets, cowls and statement pieces on large needles.

7 (jumbo). The thickest category, used for arm knitting and giant chunky blankets.

Note: the Craft Yarn Council has recently added a size 8 category to the system, but has not yet published its name or specifications. The 0 to 7 scale above remains the standard you will see on almost all yarn labels.

Worsted vs aran vs DK: the differences

These categories overlap, partly because of US/UK differences:

• DK (weight 3) is slightly thinner than worsted. It is common in UK and European patterns.
• Worsted (weight 4) is the standard US "medium".
• Aran (also weight 4) is at the thicker end of medium. It is heavier than worsted in many ranges, though the categories overlap.

When substituting, do not rely on the name alone. Check the weight number and the gauge on the label.

How to find the weight of an unlabelled yarn

If the label is missing, use wraps per inch (WPI). Wrap the yarn snugly (not stretched) around a ruler for one inch and count the wraps. Fewer wraps means thicker yarn. As a rough guide, lace wraps about 30 to 40 times per inch, while super bulky wraps only about 5 to 6 times. WPI figures vary between sources and depend on how tightly you wrap. The Craft Yarn Council itself calls WPI subjective. Treat it as an estimate and, when in doubt, knit a swatch and compare it to the gauge chart above.

Substituting yarn safely

To swap one yarn for another, match (1) the weight category, (2) the gauge, and (3) roughly the fibre and drape. The same weight number is the starting point, but always knit a gauge swatch. Two "worsted" yarns can still differ enough to change your finished size.