Yarn weight chart

“Weight” here means thickness, not how heavy the ball is. The number on the label runs 0 to 7, and it is the single most useful thing on a yarn band — get it wrong and a pattern comes out the wrong size no matter how neat your stitches are.

Most beginner patterns, including everything in Crochet Bobble’s early lessons, use medium (4) yarn with a 5.5 mm hook. It’s thick enough to see what your hands are doing.

Craft Yarn Council standard weights.
No.	Name	Also called	Hook (mm)	Hook (US)
0	Lace	Fingering, 10-count crochet thread	1.4–2.25 mm	Steel 8 to B-1
1	Super Fine	Sock, Fingering, Baby	2.25–3.5 mm	B-1 to E-4
2	Fine	Sport, Baby	3.5–4.5 mm	E-4 to 7
3	Light	DK, Light Worsted	4.5–5.5 mm	7 to I-9
4	Medium	Worsted, Afghan, Aran	5.5–6.5 mm	I-9 to K-10.5
5	Bulky	Chunky, Craft, Rug	6.5–9 mm	K-10.5 to M-13
6	Super Bulky	Super Bulky, Roving	9–15 mm	M-13 to Q
7	Jumbo	Jumbo, Roving	15– mm	Q and larger

Those hook ranges are a starting point, not a rule. If your stitches come out tight, go up a size; loose, go down. Full hook size chart here.

Tired of a notebook and four apps?

This chart lives inside Crochet Bobble, along with the rest of the toolbox: what yarn you already own, which row you were on, how much a blanket will take — in one app that works when the signal doesn’t.

Crochet Bobble opens Winter 2026 — waitlist members get 2 months free at launch, then the founder price of $7.99/mo for as long as you stay.

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