Knitting needle size chart

Knitting needles
mm	US	Yarn weights
1.5 mm	000
1.75 mm	00
2 mm	0
2.25 mm	1
2.75 mm	2
3 mm	–
3.125 mm	3
3.25 mm	3
3.5 mm	4
3.75 mm	5
4 mm	6
4.25 mm	6
4.5 mm	7
5 mm	8
5.25 mm	9
5.5 mm	9
5.75 mm	10
6 mm	10
6.5 mm	10½
7 mm	–
8 mm	11
9 mm	13
10 mm	15
12.5 mm	17
12.75 mm	17
15 mm	19
19 mm	35
25 mm	50
35 mm	70

Crochet hooks
mm	US	Yarn weights
2.25 mm	B-1
2.5 mm	–
2.75 mm	C-2
3.125 mm	D
3.25 mm	D-3
3.5 mm	E-4
3.75 mm	F-5
4 mm	G-6
4.25 mm	G
4.5 mm	7
5 mm	H-8
5.25 mm	I
5.5 mm	I-9
5.75 mm	J
6 mm	J-10
6.5 mm	K-10½
7 mm	–
8 mm	L-11
9 mm	M/N-13
10 mm	N/P-15
11.5 mm	P-16
12 mm	–
15 mm	P/Q
15.75 mm	Q
16 mm	Q
19 mm	S
25 mm	T/U/X
30 mm	T/X

Steel crochet hooks
mm	US	Yarn weights
3.5 mm	00
3.25 mm	0
2.75 mm	1
2.7 mm	00
2.55 mm	0
2.35 mm	1
2.25 mm	2
2.2 mm	2
2.1 mm	3
2 mm	4
1.9 mm	5
1.8 mm	6
1.75 mm	4/0
1.7 mm	5
1.65 mm	7
1.6 mm	6
1.5 mm	8/7/2
1.4 mm	9/8
1.3 mm	10
1.25 mm	9/4
1.15 mm	10
1.1 mm	11
1.05 mm	11
1 mm	12/6
0.95 mm	13
0.9 mm	14/8
0.85 mm	13
0.75 mm	14/10
0.6 mm	12

Find your needle in the list above by its mm or its US number, and the chart from the Craft Yarn Council (CYC) gives the other. Where you can, go by the mm, as the hint under the list says.

New to knitting? Start with the needle on your yarn label or pattern, then knit a gauge swatch to check it. A swatch is a small test square, and its gauge is how many stitches and rows fit in 4".

How to use the knitting needle size chart

Leave “Knitting needles” selected, or switch to “Crochet hooks”.
Choose your size from the list. Each entry shows the mm with the US size, as in 4 mm (US 6). Where CYC gives no US number, the list says “no US size”.
Read the result: the US size, the yarn weights for that needle (CYC’s numbered categories, 0 Lace to 7 Jumbo) and, where CYC lists one, the crochet hook of the same mm.
Find the highlighted row in the full chart above this guide. The page address keeps your choice, so you can bookmark or share it.

Knitting needle sizes: go by the mm, not the US number

CYC’s chart gives one US number to two mm sizes in five places: US 3, 6, 9, 10 and 17. US 6 is both 4 mm and 4.25 mm, and US 9 is both 5.25 mm and 5.5 mm. CYC lists no US size for 3 mm either (the 7 mm needle is in the Good to know box above), so the chart shows “–” there.

The US numbers also skip as needles get thicker: 8 mm is US 11, then 9 mm is US 13, 10 mm is US 15, and 12.5 mm and 12.75 mm are both US 17. CYC’s needle table has no 12, 14 or 16.

So when a pattern calls for “US 6”, look for the mm beside it. If there’s none, your swatch settles it. CYC says to always complete a gauge swatch and change needle size until it matches the pattern. The gauge calculator turns your swatch’s count into stitch counts for your project.

When you buy needles, pick ones marked in mm, like a bamboo needle set, circulars and straights, marked in mm from 2 mm to 10 mm ad . It has both circular needles (two tips joined by a flexible plastic tube) and single-pointed straight needles. If a needle’s size has worn off, a needle gauge ad checks it, and the same tool measures stitch gauge. For the kinds and materials, see the knitting needle types guide.

Knitting needle size and yarn weight

The yarn weights come from CYC’s recommended needle range for each yarn category. They’re ranges, not limits: CYC labels them guidelines only.

The ranges meet at their ends, so a needle on the edge of two ranges suits both weights: 4.5 mm (US 7) is for 3 Light and 4 Medium, and 5.5 mm (US 9) for 4 Medium and 5 Bulky.

CYC counts knit gauge over 4" in stockinette, the smooth fabric you get, when working flat, by knitting the right-side rows (the front of the work) and purling the wrong-side rows (the back). To find a yarn’s weight from the gauge and needle size on its label, use the yarn weight chart.

Knitting needles vs crochet hooks at the same mm

At the same mm, a crochet hook often suits a lighter yarn than a knitting needle. Besides the 5 mm example in the Good to know box above, a 4 mm needle (US 6) is for 3 Light yarn and a 4 mm hook (G-6) for 2 Fine. A 6.5 mm needle (US 10½) is for 5 Bulky, and a 6.5 mm hook (K-10½) for 4 Medium and 5 Bulky.

The same shift runs through CYC’s yarn table: from 2 Fine to 7 Jumbo, each category’s hook range starts at a larger mm than its needle range. For 2 Fine, needles run 3.25–3.75 mm and hooks 3.5–4.5 mm. So when you knit, read the needle column of a yarn chart. For crochet, use the crochet hook size chart, which lists hooks first.

FAQs

What size knitting needles should a beginner use?

Lion Brand, a yarn company, suggests learning with worsted (medium, category 4) yarn. In general, it says, that yarn “will call for a US size 7 to 9 (4.5 to 5.5 mm) needle”, though “the label should tell you for sure what size is best for that yarn.” Those are the rows from 4.5 mm (US 7) to 5.5 mm (US 9) in the chart above.

What size is a US 8 knitting needle in mm?

5 mm, and in CYC’s chart US 8 is that one size only. For the US numbers that cover two sizes, see “Knitting needle sizes: go by the mm, not the US number” above.

What size knitting needles for DK yarn?

For DK yarn, CYC lists “DK, Light Worsted” under 3 Light, with a needle range of 3.75 to 4.5 mm (US 5 to 7) in its yarn weight table. For other yarns, use the yarn weight chart.

Are knitting needle and crochet hook sizes the same?

The mm is the same measurement, but the US labels can differ: a 6 mm needle is US 10, and a 6 mm hook is J-10 (at 4.5 mm both are 7). The yarn each suits can differ too, as “Knitting needles vs crochet hooks at the same mm” above shows.