Crochet Hook Conversion Chart

Crochet hooks come in a wide variety of sizes. Hook sizes are measured by diameter in millimeters and may easily be converted to US standard hook sizes.

US Crochet Hook Size Metric/Millimeter (mm)
B/1 2.25
C/2 2.75
D/3 3.25
E/4 3.5
F/5 3.75
G/6 4.0
7 4.5
H/8 5.0
I/9 5.5
J/10 6.0
K/10.5 6.5
L/11 8.0
M/13 9.0
N/15 10.0
P 15.0
Q 16.0
S 19.0