I finally found this. I remember I asked a while ago about this but no one knew. So here it is for all of you interested:

AWG Metric | Equivalent mm sq | Metric Cable Size mm sq.
20 0.52 0.75
18 0.82 1.0
16 1.32 1.5
14 2.1 2.5
12 3.3 4
10 5.32 6
8 8.5 10
6 13.5 15
4 21.3 25
2 33.7 35
1/0 (0) 53 50
2/0 (00) 67.6 70
3/0 (000) 84.4 95
4/0 (0000) 107 120

Here's the link: http://www.mogami.com/e/cad/wire-gauge.html
Hope this is usefull. It sure was to me.