Yarn weights, needles and hooks
The Craft Yarn Council's standard yarn weight system numbers yarns from 0 (lace) to 7 (jumbo), and most ball bands print the symbol. The gauges below are the standard ranges over 4 inches: stockinette for knitting and single crochet for crochet. They are starting points, not targets; the gauge your pattern asks for is the one that counts.
| Weight | Common names | Knit gauge (sts per 4 in) | Needles (US) | Needles (mm) | Crochet gauge (sc per 4 in) | Hooks (US) | Hooks (mm) |
|---|---|---|---|---|---|---|---|
| 0 Lace | Fingering, 10-count thread | 33–40 | 000–1 | 1.5–2.25 | 32–42 (double crochet) | Steel 6–8, B-1 | 1.4–2.25 |
| 1 Super Fine | Sock, fingering, baby | 27–32 | 1–3 | 2.25–3.25 | 21–32 | B-1 to E-4 | 2.25–3.5 |
| 2 Fine | Sport, baby | 23–26 | 3–5 | 3.25–3.75 | 16–20 | E-4 to 7 | 3.5–4.5 |
| 3 Light | DK, light worsted | 21–24 | 5–7 | 3.75–4.5 | 12–17 | 7 to I-9 | 4.5–5.5 |
| 4 Medium | Worsted, afghan, aran | 16–20 | 7–9 | 4.5–5.5 | 11–14 | I-9 to K-10½ | 5.5–6.5 |
| 5 Bulky | Chunky, craft, rug | 12–15 | 9–11 | 5.5–8 | 8–11 | K-10½ to M-13 | 6.5–9 |
| 6 Super Bulky | Super bulky, roving | 7–11 | 11–17 | 8–12.75 | 7–9 | M-13 to Q | 9–15 |
| 7 Jumbo | Jumbo, roving | 6 or fewer | 17 and larger | 12.75 and larger | 6 or fewer | Q and larger | 15 and larger |
Lace-weight yarns are often knitted on larger needles than the chart suggests to open up the fabric, so lace patterns state their own gauge.
Which calculator do you need?
Start with a swatch. The knitting gauge calculator turns it into a cast-on count and a row count for any width and length, rounds to your stitch multiple, and rescales a pattern written for a different gauge. The crochet blanket size calculator gives standard blanket sizes and the starting chain and rows for each at your gauge. When you know the size, the yarn calculator uses the same swatch to work out how many yards and skeins to buy.