Knitting needles
Knitting Needle Sizes: US, Metric and Old UK Conversions for Every Size
Knitting needles are sized by diameter in millimeters. US sizes run from 000 (1.5 mm) to 70 (35 mm), and old UK sizes run in reverse, from 14 (2 mm) to 000 (10 mm). US 8, the classic worsted size, is 5 mm. Always check the millimeter size.
The table below converts every knitting needle size between metric, US and old UK numbers and shows the yarn weights each one suits: US 8, the most common size, is 5 mm and suits medium (worsted) yarn.
| Metric | US | Old UK and Canadian | Yarn weights (CYC) | Size guide |
|---|---|---|---|---|
| 1.5 mm | 000 | None | lace | US 000 guide |
| 1.75 mm | 00 | None | lace | US 00 guide |
| 2 mm | 0 | 14 | lace | US 0 guide |
| 2.25 mm | 1 | 13 | lace, super fine (fingering) | US 1 guide |
| 2.5 mm | None | None | super fine (fingering) | 2.5 mm guide |
| 2.75 mm | 2 | 12 | super fine (fingering) | US 2 guide |
| 3 mm | 3 | 11 | super fine (fingering) | US 3 guide |
| 3.125 mm | 3 | None | super fine (fingering) | See nearest size |
| 3.25 mm | 3 | 10 | super fine (fingering), fine (sport) | US 3 guide |
| 3.5 mm | 4 | None | fine (sport) | US 4 guide |
| 3.75 mm | 5 | 9 | fine (sport), light (DK) | US 5 guide |
| 4 mm | 6 | 8 | light (DK) | US 6 guide |
| 4.25 mm | 6 | None | light (DK) | See nearest size |
| 4.5 mm | 7 | 7 | light (DK), medium (worsted) | US 7 guide |
| 5 mm | 8 | 6 | medium (worsted) | US 8 guide |
| 5.25 mm | 9 | None | medium (worsted) | See nearest size |
| 5.5 mm | 9 | 5 | medium (worsted), bulky (chunky) | US 9 guide |
| 5.75 mm | 10 | None | bulky (chunky) | See nearest size |
| 6 mm | 10 | 4 | bulky (chunky) | US 10 guide |
| 6.5 mm | 10.5 | 3 | bulky (chunky) | US 10.5 guide |
| 7 mm | None | 2 | bulky (chunky) | 7 mm guide |
| 7.5 mm | None | 1 | bulky (chunky) | See nearest size |
| 8 mm | 11 | 0 | bulky (chunky), super bulky | US 11 guide |
| 9 mm | 13 | 00 | super bulky | US 13 guide |
| 10 mm | 15 | 000 | super bulky | US 15 guide |
| 12.5 mm | 17 | None | super bulky | See nearest size |
| 12.75 mm | 17 | None | super bulky, jumbo | US 17 guide |
| 15 mm | 19 | None | jumbo | US 19 guide |
| 19 mm | 35 | None | jumbo | See nearest size |
| 25 mm | 50 | None | jumbo | See nearest size |
| 35 mm | 70 | None | jumbo | See nearest size |
Old UK and Canadian sizes run in reverse: higher numbers are finer needles. Less common in-between sizes share a page with their nearest standard size, so 3.125 mm is covered on US 3 (3.25 mm) and 5.25 mm on US 9 (5.5 mm), and the jumbo 19, 25 and 35 mm sizes are covered on the 15 mm page. At the other end, US 0 (2 mm) and finer are lace and thread territory. Measure your own gauge with the knitting gauge calculator, see the printable knitting needle size chart, or match hooks on the crochet hook size guide.
Frequently asked questions
What size knitting needles should a beginner use?
US 8, which is 5 mm, with worsted weight yarn is the usual starting point. Worsted knits at 16 to 20 stitches per 4 inches, big enough to see and count without looking coarse, and US 7 to 9 (4.5 to 5.5 mm) all suit it. Smooth, light-colored yarn makes dropped stitches much easier to spot than dark or fuzzy yarn.
What knitting needle size do you use for worsted weight yarn?
CYC lists 4.5 to 5.5 mm (US 7 to 9) needles for worsted weight yarn, and US 8 (5 mm) is the most common of the three. Expect 16 to 20 stitches per 4 inches in stockinette. If your swatch has fewer stitches than the pattern your knitting is loose, so go down a size; if it has more, go up.
How do I measure knitting needle size?
Push the needle through the holes of a needle gauge until you find the one it passes through snugly; that hole is marked in millimeters and usually in US sizes too. Millimeters are the only figure that matches across brands, because US numbers were never fully standardized: some charts call 3 mm US 3 and others US 2.5. A needle gauge is inexpensive and settles every unlabeled needle in a stash.
Are US and old UK knitting needle sizes the same?
No, and they count in opposite directions. US numbers grow with the needle, from US 000 at 1.5 mm up to US 19 at 15 mm and beyond, while old UK and Canadian numbers shrink, from 14 at 2 mm down to 000 at 10 mm. US 8 and old UK 6 are the same 5 mm needle. When a pattern gives a bare number, work out which system it uses, or follow the millimeter size.
Researched from manufacturer specifications, owner manuals and verified owner reviews, not hands-on testing, and not professional advice. As an Amazon Associate, Cozy Stitchery earns from qualifying purchases.
