Free shipping - usa orders over $25*

Knitting Needle and Crochet Hook Size Chart

Ensuring that your knitting needle or crochet hook is the right size is critical to get your project started on the right foot. 

We get the question all the time... which is better to use, the "number size" or the "mm size" when referring to knitting needles and crochet hooks? The answer is simple: the mm (or millimeter) size is the only size that remains constant across all product brands and geographies around the world. The number size, typically marked with a "#" or "No." before the numeral, is generally unreliable since the referenced product and the marking on your tool could be different. 

Please refer to the charts below to correlate the mm size with the number size for knitting needles and crochet hooks in North America (US Size). 

 

Knitting Needles Size Chart - MM Size to US # Size

Millimeter Size (mm)       U.S. Number Size (#)

2 mm .....................................0
2.25 mm .............................. 1
2.75 mm ...............................2
3.25 mm ...............................3
3.5 mm .................................4
3.75 mm ...............................5
4 mm ....................................6
4.5 mm .................................7
5 mm ....................................8
5.5 mm .................................9
6 mm ....................................10
6.5 mm .................................10.5
7 mm ....................................10.75
8 mm ....................................11
9 mm ....................................13
10 mm ..................................#15
12 mm ..................................#16
12.75 mm .............................#17
15 mm ..................................#19
19 mm ..................................#35
25 mm ..................................#50

Crochet Hook Size Chart - MM Size to US # Size

Millimeter Size (mm)       U.S. Number Size (#)

2 mm .....................................0
2.25 mm ...............................B - 1
2.75 mm ...............................C - 2
3.25 mm ...............................D - 3
3.5 mm .................................E - 4
3.75 mm ...............................F - 5
4 mm ....................................G - 6
4.5 mm .................................7
5 mm ....................................H - 8
5.5 mm .................................I - 9
6 mm ....................................J - 10
6.5 mm .................................K - 10.5
8 mm ....................................L - 11
9 mm ....................................M/N - 13
10 mm ..................................N/P - 15
15 mm ..................................P/Q
16 mm ..................................Q
19 mm ..................................S

 

 

Have a question about sizing? Please contact us and we'll be happy to help you out!