We made this Fraction to in to mm chart for ourselves and figured you could use it too.
Fraction Decimal Value MM
1/64 0.015625 0.396875
1/32 0.03125 0.79375
3/64 0.046875 1.190625
1/16 0.0625 1.5875
5/64 0.078125 1.984375
3/32 0.09375 2.38125
7/64 0.109375
1/8 0.125
9/64 0.140625
5/32 0.15625
11/64 0.171875
3/16 0.1875
13/64 0.203125
7/32 0.21875
15/64 0.234375
1/4 0.25
17/64 0.265625
9/32 0.28125
19/64 0.296875
5/16 0.3125
21/64 0.328125
11/32 0.34375
23/64 0.359375
3/8 0.375
25/64 0.390625
13/32 0.40625
27/64 0.421875
7/16 0.4375
29/64 0.453125
15/32 0.46875
31/64 0.484375
1/2 0.5
33/64 0.515625
17/32 0.53125
35/64 0.546875
9/16 0.5625
37/64 0.578125
19/32 0.59375
39/64 0.609375
5/8 0.625
41/64 0.640625
21/32 0.65625
43/64 0.671875
11/16 0.6875
45/64 0.703125
23/32 0.71875
47/64 0.734375
3/4 0.75
49/64 0.765625
25/32 0.78125
51/64 0.796875
13/16 0.8125
53/64 0.828125
27/32 0.84375
55/64 0.859375
7/8 0.875
57/64 0.890625
29/32 0.90625
59/64 0.921875
15/16 0.9375
61/64 0.953125
31/32 0.96875
63/64 0.984375