This table of equivalents should be useful for drill bit sizes, wrench and socket sizes, etc.

Inch/mm equivalents table

inch/64	Fractional inch	Decimal inch	mm
1	1/64	0.015625	0.396875
2	1/32	0.03125	0.79375
3	3/64	0.046875	1.190625
4	1/16	0.0625	1.5875
5	5/64	0.078125	1.984375
6	3/32	0.09375	2.38125
7	7/64	0.109375	2.778125
8	1/8	0.125	3.175
9	9/64	0.140625	3.571875
10	5/32	0.15625	3.96875
11	11/64	0.171875	4.365625
12	3/16	0.1875	4.7625
13	13/64	0.203125	5.159375
14	7/32	0.21875	5.55625
15	15/64	0.234375	5.953125
16	1/4	0.25	6.35
17	17/64	0.265625	6.746875
18	9/32	0.28125	7.14375
19	19/64	0.296875	7.540625
20	5/16	0.3125	7.9375
21	21/64	0.328125	8.334375
22	11/32	0.34375	8.73125
23	23/64	0.359375	9.128125
24	3/8	0.375	9.525
25	25/64	0.390625	9.921875
26	13/32	0.40625	10.31875
27	27/64	0.421875	10.715625
28	7/16	0.4375	11.1125
29	29/64	0.453125	11.509375
30	15/32	0.46875	11.90625
31	31/64	0.484375	12.303125
32	1/2	0.5	12.7
33	33/64	0.515625	13.096875
34	17/32	0.53125	13.49375
35	35/64	0.546875	13.890625
36	9/16	0.5625	14.2875
37	37/64	0.578125	14.684375
38	19/32	0.59375	15.08125
39	39/64	0.609375	15.478125
40	5/8	0.625	15.875
41	41/64	0.640625	16.271875
42	21/32	0.65625	16.66875
43	43/64	0.671875	17.065625
44	11/16	0.6875	17.4625
45	45/64	0.703125	17.859375
46	23/32	0.71875	18.25625
47	47/64	0.734375	18.653125
48	3/4	0.75	19.05
49	49/64	0.765625	19.446875
50	25/32	0.78125	19.84375
51	51/64	0.796875	20.240625
52	13/16	0.8125	20.6375
53	53/64	0.828125	21.034375
54	27/32	0.84375	21.43125
55	55/64	0.859375	21.828125
56	7/8	0.875	22.225
57	57/64	0.890625	22.621875
58	29/32	0.90625	23.01875
59	59/64	0.921875	23.415625
60	15/16	0.9375	23.8125
61	61/64	0.953125	24.209375
62	31/32	0.96875	24.60625
63	63/64	0.984375	25.003125