Yarn Weight (Thickness)

By Pam Allen, Tracy Barr, and Shannon Okey from Knitting For Dummies, 2nd Edition

Knitting and crochet yarns come in different weights, or thicknesses. The thickness of your yarn (among other factors) has a huge impact on the look of your knitted or crocheted fabric — and certainly the amount of time it takes to complete it. Yarn weight determines how many stitches it takes to knit 1 inch.

Although there are no official categories for yarn weights, many knitting books and yarn manufacturers use common terms to indicate a yarn’s thickness and the size of the needle with which you work on the yarn.

      

Common Yarn Weights

Yarn Weight	Number ID and Symbol	US Needle Size	Knitting Stitches Per Inch, in Stockinette Stitch	Common Uses
Lace		000–1	8–10	Lace knitting
Super fine, fingering, or baby-weight		1–3	7–8	Light layettes, socks
Fine or sport-weight		3–6	5–6	Light sweaters, baby things, accessories
Light worsted or DK (double-knitting)		5–7	5–5 1/2	Sweaters and other garments, lightweight scarves
Medium- or worsted-weight, afghan, Aran		7–9	4–5	Sweaters, blankets, outdoor wear (hats, scarves, mittens, and so on)
Bulky or chunky		10–11	3–3 1/2	Rugs, jackets, blankets
Super bulky		13–15	2–2 1/2	Heavy blankets and rugs, sweaters

The thickness of a given yarn is determined by the individual thickness of the plies, not by the number of plies. If the plies are thin, a 4-ply yarn can be finer than a heavy, single-ply yarn.