This was TOTALLY mooched from the Purple Kitty site, I do not claim to have any hand in creating this, only finding it. Thank you folks over at the purple kitty for giving us so many good things for us fiber addicts!!!

For working up the Brit / wicked old patterns that are so enchanting. Sorry about the lining up in the chart below, but there is also the link to the Purple Kitty site where I mooched this from.
KNITTING NEEDLE CONVERSION
Metric (mm) | US| UK/Canada
2 | 0 | 14
2.25| 1 | 13
2.75 | 2 | 12
3 | -- | 11
3.25| 3 | 10
3.50 | 4 | --
3.75 | 5 | 9
4.00 | 6 | 8
4.50 | 7 | 7
5.00 | 8 | 6
5.50 | 9 | 5
6.00 | 10 | 4
6.50 | 10.5| 3
7.00 | -- | 2
7.50 | -- | 1
8.00 | 11 | 0
9.00 | 13 | 00
10.0 | 15 | 000
12.0 | 17 | --
16.0 | 19 | --
19.0 | 35 | --
25.0 | 50 | --

link text