Metric - UK Needle and Hook Conversion Chart.

Metric UK Size
1.75mm 15
2.0mm 14
2.25mm 13
2.75mm 12
3.0mm 11
3.25mm 10
3.5mm -
3.75mm 9
4.0mm 8
4.5mm 7
5.0mm 6
5.5mm 5
6.0mm 4
6.5mm 3
7.0mm 2
7.5mm 1
8.0mm 0
9.0mm 00
10.0mm 000