Needle and hook size converter
Type a size the way it is written on the needle, the pattern or the hook — 5mm, US 8, UK 6, G — and see what it is in every other notation. The full charts are below.
Knitting needles
| US | mm | Old UK | Usually knits |
|---|---|---|---|
| 000 | 1.5 | 16 | Lace |
| 00 | 1.75 | 15 | Lace |
| 0 | 2 | 14 | Lace, fine fingering |
| 1 | 2.25 | 13 | Fingering, socks |
| 1.5 | 2.5 | — | Socks |
| 2 | 2.75 | 12 | Fingering |
| 2.5 | 3 | 11 | Fingering |
| 3 | 3.25 | 10 | Fingering, sport |
| 4 | 3.5 | — | Sport |
| 5 | 3.75 | 9 | Sport, DK |
| 6 | 4 | 8 | DK |
| 7 | 4.5 | 7 | DK, worsted |
| 8 | 5 | 6 | Worsted |
| 9 | 5.5 | 5 | Worsted, aran |
| 10 | 6 | 4 | Aran, chunky |
| 10.5 | 6.5 | 3 | Chunky |
| 10.75 | 7 | 2 | Chunky |
| 11 | 8 | 0 | Bulky |
| 13 | 9 | 00 | Bulky |
| 15 | 10 | 000 | Bulky, super bulky |
| 17 | 12 | — | Super bulky |
| 19 | 15 | — | Super bulky |
| 35 | 19 | — | Jumbo |
| 50 | 25 | — | Jumbo |
Millimeters are the size; the US and UK numbers are names for them, and the old UK scale runs the other way. Makers round differently at the small end — addi's US 1 is 2.5 mm where the chart says 2.25 — so match the millimeters stamped on the needle to the millimeters in the pattern. Every needle we sell is listed by its maker's own label, and the needle size guide says which size suits which yarn.
Crochet hooks
| US letter / number | mm | Usually works |
|---|---|---|
| B-1 | 2.25 | Lace, fingering |
| C-2 | 2.75 | Fingering |
| D-3 | 3.25 | Fingering, sport |
| E-4 | 3.5 | Sport |
| F-5 | 3.75 | Sport, DK |
| G-6 | 4 | DK |
| 7 | 4.5 | DK, light worsted |
| H-8 | 5 | Worsted |
| I-9 | 5.5 | Worsted |
| J-10 | 6 | Worsted, aran |
| K-10½ | 6.5 | Chunky |
| L-11 | 8 | Bulky |
| M/N-13 | 9 | Bulky |
| N/P-15 | 10 | Super bulky |
| P/Q | 15 | Jumbo |
| S | 19 | Jumbo |
The letters are the Craft Yarn Council's pairings and makers disagree with them: addi's G is 4.5 mm and its K is 7. Buy by the millimeters. The crochet hook guide covers which hook for which yarn and why crochet takes more of it.
Steel thread hooks
| Steel size | mm |
|---|---|
| 00 | 3.5 |
| 0 | 3.25 |
| 1 | 2.75 |
| 2 | 2.25 |
| 4 | 2 |
| 6 | 1.8 |
| 8 | 1.5 |
| 10 | 1.3 |
| 12 | 1 |
| 14 | 0.75 |
A higher steel number is a finer hook.
Weight categories follow the Craft Yarn Council standards. Source: Craft Yarn Council, www.YarnStandards.com.
The guides behind the numbers
- GuideWhich circular needle length do I need?How to pick a circular needle's cable length for hats, sleeves, sweaters, shawls and blankets, when to use magic loop instead, and the difference between addi Turbo, Rockets and bamboo.
- GuideCrochet hook sizes: letters, numbers and millimetersEvery crochet hook size from steel thread hooks to jumbo with its millimeters, why the US letters disagree between makers, which hook goes with which yarn weight, why crochet uses more yarn than knitting, and the addi Swing, Comfort Grip and Crystal Palace hooks we stock.
- GuideKnitting needle sizes: US, metric and UK chartEvery knitting needle size from US 000 to US 50 with its millimeter and old UK equivalent, which size goes with which yarn weight, why the maker's stamp beats the chart, and the crochet hook letters alongside.
More tools
- Yardage estimator — How many yards a sweater, blanket, hat, scarf, cowl, mittens, socks, shawl or baby cardigan takes at each yarn weight, and how many skeins that is.
- Gauge calculator — Your stitches and rows per inch from a swatch, how many needle sizes to move to hit a pattern's gauge, and the cast-on for any width at your gauge.