Knitting Needle + Crochet Hook Size Conversions

Metric (mm) + U.S. Knitting Needle Conversions

Metric Sizes (mm)  U.S. Sizes
2 mm 0
2.5 mm  1
2.75 mm 2
3 mm 2 1/2 
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 1/2 
7 mm -
7.5 mm -
8 mm 11
9 mm 13
10 mm 15
12 mm 17
16 mm 19
19 mm 35
20 mm 36
25 mm 50

 

Mertic (mm) + U.S. Crochet Hook Conversions

Metric Sizes (mm)  U.S. Sizes
0.60 mm 14
0.75 mm 12
1 mm 10
1.25 mm -
1.5 mm 6
1.75 mm 4
2 - 2.25 mm B
2.75 mm  C
3.25 mm D
3.5 mm E
3.75 mm F
4 mm G
4.5 mm G
5 mm H
5.5 mm I
6 mm J
6.5 mm 10 1/2 
7 mm -
7.5 mm -
8 mm L
9 mm M/N
10 mm N/P
11 mm P
12 mm 17
15 mm P/Q
16 mm Q
17.5 mm R
19 mm S
20 mm 36
25 mm 50
30 mm T/X