Knitting needle & crochet hook size chart: US, UK and metric
Key takeaways
- Metric (mm) is the only unambiguous system — the Craft Yarn Council itself says to rely on it because US letters and numbers vary between manufacturers.
- Old UK/Canadian needle sizes run in reverse: 14 is a thin 2 mm needle, 0 is a chunky 8 mm.
- A US 8 is not a UK 8 — one is 5 mm, the other 4 mm.
- Print this page (Ctrl/Cmd-P): the print layout strips everything but the tables.
Every conversion below is traced to two published charts, cross-checked against each other on 2026-11-16: the Craft Yarn Council hooks & needles size chart (metric ↔ US) and the Vogue Knitting needle conversion chart (metric ↔ US ↔ UK). A dash means that size does not exist in that system — for example 3 mm needles were only ever sold in UK sizing (UK 11).
Knitting needles — metric / US / old UK-Canada
| Metric (mm) | US size | UK / Canada |
|---|---|---|
| 1.50 | 000 | — |
| 1.75 | 00 | — |
| 2.00 | 0 | 14 |
| 2.25 | 1 | 13 |
| 2.75 | 2 | 12 |
| 3.00 | — | 11 |
| 3.25 | 3 | 10 |
| 3.50 | 4 | — |
| 3.75 | 5 | 9 |
| 4.00 | 6 | 8 |
| 4.50 | 7 | 7 |
| 5.00 | 8 | 6 |
| 5.50 | 9 | 5 |
| 6.00 | 10 | 4 |
| 6.50 | 10½ | 3 |
| 7.00 | — | 2 |
| 7.50 | — | 1 |
| 8.00 | 11 | 0 |
| 9.00 | 13 | 00 |
| 10.00 | 15 | 000 |
| 12.00 | 17 | — |
| 12.75 | 17 | — |
| 15.00 | 19 | — |
| 16.00 | 19 | — |
| 19.00 | 35 | — |
| 25.00 | 50 | — |
| 35.00 | 70 | — |
Crochet hooks — metric / US letter
| Metric (mm) | US size |
|---|---|
| 2.25 | B-1 |
| 2.75 | C-2 |
| 3.125 | D |
| 3.25 | D-3 |
| 3.50 | E-4 |
| 3.75 | F-5 |
| 4.00 | G-6 |
| 4.25 | G |
| 4.50 | 7 |
| 5.00 | H-8 |
| 5.25 | I |
| 5.50 | I-9 |
| 5.75 | J |
| 6.00 | J-10 |
| 6.50 | K-10½ |
| 8.00 | L-11 |
| 9.00 | M/N-13 |
| 10.00 | N/P-15 |
| 11.50 | P-16 |
| 15.00 | P/Q |
| 15.75 | Q |
| 16.00 | Q |
| 19.00 | S |
| 25.00 | T/U/X |
Steel hooks for thread crochet (roughly 1.4–1.6 mm) are sized in reverse: the higher the steel number, the smaller the hook (CYC weight chart: steel 6, 7, 8 for lace-category thread work).
Yarn weight categories at a glance
Craft Yarn Council Standard Yarn Weight System, knit gauge in stitches per 10 cm / 4", with guideline needle and hook ranges. CYC's own label: "guidelines only".
| CYC # | Name | Knit gauge (sts / 10 cm) | Needles | Hooks |
|---|---|---|---|---|
| 0 | Lace | 33–40 | 1.5–2.25 mm (US 000–1) | Steel 1.4–1.6 mm / 2.25 mm |
| 1 | Super Fine (fingering, sock) | 27–32 | 2.25–3.25 mm (US 1–3) | 2.25–3.5 mm (B-1–E-4) |
| 2 | Fine (sport, baby) | 23–26 | 3.25–3.75 mm (US 3–5) | 3.5–4.5 mm (E-4–7) |
| 3 | Light (DK, light worsted) | 21–24 | 3.75–4.5 mm (US 5–7) | 4.5–5.5 mm (7–I-9) |
| 4 | Medium (worsted, aran) | 16–20 | 4.5–5.5 mm (US 7–9) | 5.5–6.5 mm (I-9–K-10½) |
| 5 | Bulky (chunky) | 12–15 | 5.5–8 mm (US 9–11) | 6.5–9 mm (K-10½–M-13) |
| 6 | Super Bulky | 7–11 | 8–12.75 mm (US 11–17) | 9–15 mm (M-13–Q) |
| 7 | Jumbo | 6 or fewer | 12.75 mm+ (US 17+) | 15 mm+ (Q+) |
Why three systems exist (and how to stay sane)
Needle sizing is a museum of history. US sizes were arbitrary manufacturer numbers that stuck; the old UK/Canadian system counted wire gauges, so it runs backwards — a UK 14 (2 mm) is thinner than a UK 0 (8 mm). Modern manufacturers increasingly label only millimetres, and the Craft Yarn Council's chart notes that letter and number sizing "vary from company to company", which is why metric is the column to trust.
Two practical habits follow. First, when a vintage pattern says "No. 10 needles", check whether it is British — that is 3.25 mm, not a US 10 (6 mm), and the difference is a whole garment size. Second, when a pattern's stated gauge matters more than its stated needle (almost always), treat the needle size as a starting point and swatch — the gauge is the actual specification.
The weight-category table above is the industry's shared language for pairing yarn with tools: it is the same table the yarn calculator uses to infer your yarn's category from stitch gauge, and it pairs naturally with the ball-band fields explained in reading a yarn label.
Related
- Standard body measurement tables — the other printable cheat sheet
- Pattern Resize Calculator — put the gauge math to work
- Knitting math explained — gauge to dimensions