Crochet Bobble

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.NameAlso called Hook (mm)Hook (US)
0 Lace Fingering, 10-count crochet thread 2.25–2.25 mm Steel 6, 7, 8 or 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, and the gauge calculator turns a swatch into the numbers a pattern is asking for.

Tap a weight above for the hooks it takes, the gauge to expect and what it is for. Print this chart →

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 November 24 — waitlist members get 2 months free at launch, then the founder price of $7.99/mo for as long as you stay. US only for now.

Live somewhere else? Get an email when we open in your country.