Yarn Weight Chart

0 to 7

Pick a weight to see its gauge and tools, or use the full chart to swap yarns and decode UK and Australian ply names.

Quick answer. Worsted is weight 4, Medium (10 ply), DK is weight 3, Light (8 ply) and chunky is weight 5, Bulky (12 ply).

Source: Craft Yarn Council, Standard Yarn Weight System; ply names from Ravelry.

4 Medium (10 ply in the UK and Australia): knit 16 to 20 stitches per 4 in on 4.5 to 5.5 mm needles, or crochet with a 5.5 to 6.5 mm hook.

Standard yarn weight chart

Yarn weights with names, ply, gauge, needles and hooks
WeightAlso calledUK and AU plyKnit per 4 inNeedleCrochet per 4 inHook
0 Lace Fingering, 10-count crochet thread 1 to 3 ply 33 to 40 1.5 to 2.25 mm (US 000 to 1) 32 to 42 dc steel 1.4 to 1.6 mm, regular 2.25 mm (steel 6, 7, 8; regular B-1)
1 Super Fine Sock, fingering, baby 4 ply 27 to 32 2.25 to 3.25 mm (US 1 to 3) 21 to 32 2.25 to 3.5 mm (B-1 to E-4)
2 Fine Sport, baby 5 ply 23 to 26 3.25 to 3.75 mm (US 3 to 5) 16 to 20 3.5 to 4.5 mm (E-4 to 7)
3 Light DK, light worsted 8 ply 21 to 24 3.75 to 4.5 mm (US 5 to 7) 12 to 17 4.5 to 5.5 mm (7 to I-9)
4 Medium Worsted, afghan, aran 10 ply 16 to 20 4.5 to 5.5 mm (US 7 to 9) 11 to 14 5.5 to 6.5 mm (I-9 to K-10 1/2)
5 Bulky Chunky, craft, rug 12 ply 12 to 15 5.5 to 8 mm (US 9 to 11) 8 to 11 6.5 to 9 mm (K-10 1/2 to M-13)
6 Super Bulky Super bulky, roving none 7 to 11 8 to 12.75 mm (US 11 to 17) 7 to 9 9 to 15 mm (M-13 to Q)
7 Jumbo Jumbo, roving none 6 and fewer 12.75 mm and larger (US 17 and larger) 6 and fewer 15 mm and larger (Q and larger)

Knit gauge is stockinette, crochet gauge is single crochet (double crochet for lace). The Craft Yarn Council calls these guidelines only.

Substituting yarn

  1. Match the weight number on the label, or the gauge printed on it.
  2. Work out total length: skeins in the pattern x yards per skein.
  3. Divide by the new yarn's yards per skein and round up.
  4. Swatch. Fibre changes drape and size even at the same weight.

UK and Australian ply names

Ply once meant the number of strands. Today it is just a name: 4 ply is fingering, 8 ply is DK, 10 ply is worsted or aran, and 12 ply is chunky. Lace yarn is 1 to 3 ply.

Sources

Common questions

What weight is worsted yarn?
Worsted is weight 4, Medium, along with afghan and aran. It knits at 16 to 20 stitches per 4 in on 4.5 to 5.5 mm needles.
Is DK the same as worsted?
No. DK is weight 3, Light, and is thinner than worsted (weight 4). DK knits at 21 to 24 stitches per 4 in.
What weight is 8 ply yarn?
8 ply is the UK and Australian name for DK, weight 3 Light.
What is 4 ply yarn in US terms?
4 ply is fingering or sock yarn, weight 1 Super Fine.
What weight is chunky yarn?
Chunky is weight 5, Bulky, with craft and rug yarn. 12 ply is the UK and Australian name.
Can I substitute one yarn weight for another?
Swap within the same weight number and check gauge. Moving up or down a weight changes the size of the finished piece unless you redo the stitch counts.