Needle & Hook Sizes
Three sizing systems exist for knitting needles, and two for crochet hooks, and none of them were designed with the others in mind. This section is the full reference table, broken into one page per size so each one can carry its own specific gauge notes and pairing advice rather than a bare number in a chart.
The one fact worth remembering before anything else
US and metric needle sizes climb together — bigger US number, bigger needle. UK/Canada (old) sizing was built backward from that: its number shrinks as the needle grows, past zero and into a 00-then-000 notation reserved for the very largest traditional sizes. Carry that one fact into any vintage British pattern and you'll avoid the single most common sizing mix-up on this whole reference.
Knitting needles, US 0000 through 50
- US 0 · US 1 · US 2 · US 3 · US 4 · US 5 · US 6 · US 7
- US 8 · US 9 · US 10 · US 10.5 · US 11 · US 13 · US 15
Crochet hooks, US B-1 through K-10.5
How to use this section
If you know the size a pattern calls for, go straight to that page for its metric/UK equivalents and what it's typically paired with. If you're not sure which size to reach for at all, start from a yarn weight guide instead — every weight lists its own recommended needle and hook range, which narrows the search before you need this level of detail.
When a single conversion is all you need
Skip the browsing entirely and use the Needle & Hook Size Converter — enter any one size in any system and get the other two back immediately, without hunting through the list.
FAQ
Do all needle materials (wood, metal, plastic) use the same size numbers? Yes — size refers to diameter alone; material affects grip, stitch slide, and weight in hand, not the sizing system itself.
Why does this section stop at US 15 for needles and K-10.5 for hooks? Those are the sizes with genuine, distinct pairing advice worth a full page; sizes beyond them (up through jumbo/arm-knitting territory) are covered in less granular detail within the relevant yarn weight guides instead.
Are steel crochet hooks (for fine lace thread) covered in this section? Not with their own individual pages currently — steel hooks use a distinct, finer numeric scale from the standard aluminum/plastic range covered here, noted on the lace weight guide where that separate system actually comes up.