Metric Conversions

The purpose of this document is to provide metric conversions of all listed ring sizes (by inner diameter) and wire sizes used on this website (a slightly broader range in the case of ring IDs), for those viewers of this site who prefer to use that system.

The conversion used is simple: inches * 25.4 = mm. For example, a 1/4" ring would be (0.25 * 25.4 = 6.35 mm).



Listed Ring Inner Diameters

InchesDecimal InchesMillimeters
1/128"0.0078125"0.1984375 mm
1/64"0.0156250"0.396875 mm
3/128"0.0234375"0.5953125 mm
1/32"0.0312500"0.79375 mm
5/128"0.0390625"0.9921875 mm
3/64"0.0468750"1.190625 mm
7/128"0.0546875"1.3890625 mm
.057"0.0570000"1.4478 mm
1/16"0.0625000"1.5875 mm
9/128"0.0703125"1.7859375 mm
5/64"0.0781250"1.984375 mm
11/128"0.0859375"2.1828125 mm
3/32"0.0937500"2.38125 mm
13/128"0.1015625"2.5796875 mm
7/64"0.1093750"2.778125 mm
15/128"0.1171875"2.9765625 mm
1/8"0.1250000"3.175 mm
17/128"0.1328125"3.3734375 mm
9/64"0.1406250"3.571875 mm
19/128"0.1484375"3.7703125 mm
5/32"0.1562500"3.96875 mm
21/128"0.1640625"4.1671875 mm
11/64"0.1718750"4.365625 mm
23/128"0.1796875"4.5640625 mm
3/16"0.1875000"4.7625 mm
25/128"0.1953125"4.9609375 mm
13/64"0.2031250"5.159375 mm
27/128"0.2109375"5.3578125 mm
7/32"0.2187500"5.55625 mm
29/128"0.2265625"5.7546875 mm
15/64"0.2343750"5.953125 mm
31/128"0.2421875"6.1515625 mm
1/4"0.2500000"6.35 mm
33/128"0.2578125"6.5484375 mm
17/64"0.2656250"6.746875 mm
35/128"0.2734375"6.9453125 mm
9/32"0.2812500"7.14375 mm
37/128"0.2890625"7.3421875 mm
19/64"0.2968750"7.540625 mm
39/128"0.3046875"7.7390625 mm
5/16"0.3125000"7.9375 mm
41/128"0.3203125"8.1359375 mm
21/64"0.3281250"8.334375 mm
43/128"0.3359375"8.5328125 mm
11/32"0.3437500"8.73125 mm
45/128"0.3515625"8.9296875 mm
23/64"0.3593750"9.128125 mm
47/128"0.3671875"9.3265625 mm
3/8"0.3750000"9.525 mm
49/128"0.3828125"9.7234375 mm
25/64"0.3906250"9.921875 mm
51/128"0.3984375"10.1203125 mm
13/32"0.4062500"10.31875 mm
53/128"0.4140625"10.5171875 mm
27/64"0.4218750"10.715625 mm
55/128"0.4296875"10.9140625 mm
7/16"0.4375000"11.1125 mm
57/128"0.4453125"11.3109375 mm
29/64"0.4531250"11.509375 mm
59/128"0.4609375"11.7078125 mm
15/32"0.4687500"11.90625 mm
61/128"0.4765625"12.1046875 mm
31/64"0.4843750"12.303125 mm
63/128"0.4921875"12.5015625 mm
1/2"0.5000000"12.7 mm
65/128"0.5078125"12.8984375 mm
33/64"0.5156200"13.096748 mm
67/128"0.5234375"13.2953125 mm
17/32"0.5312500"13.49375 mm
69/128"0.5390625"13.6921875 mm
35/64"0.5468700"13.890498 mm
71/128"0.5546875"14.0890625 mm
9/16"0.5625000"14.2875 mm
73/128"0.5703125"14.4859375 mm
37/64"0.5781200"14.684248 mm
75/128"0.5859375"14.8828125 mm
19/32"0.5937500"15.08125 mm
77/128"0.6015625"15.2796875 mm
39/64"0.6093700"15.477998 mm
79/128"0.6171875"15.6765625 mm
5/8"0.6250000"15.875 mm
81/128"0.6328125"16.0734375 mm
41/64"0.6406200"16.271748 mm
83/128"0.6484375"16.4703125 mm
21/32"0.6562500"16.66875 mm
85/128"0.6640625"16.8671875 mm
43/64"0.6718700"17.065498 mm
87/128"0.6796875"17.2640625 mm
11/16"0.6875000"17.4625 mm
89/128"0.6953125"17.6609375 mm
45/64"0.7031200"17.859248 mm
91/128"0.7109375"18.0578125 mm
23/32"0.7187500"18.25625 mm
93/128"0.7265625"18.4546875 mm
47/64"0.7343700"18.652998 mm
95/128"0.7421875"18.8515625 mm
3/4"0.7500000"19.05 mm
97/128"0.7578125"19.2484375 mm
49/64"0.7656200"19.446748 mm
99/128"0.7734375"19.6453125 mm
25/32"0.7812500"19.84375 mm
101/128"0.7890625"20.0421875 mm
51/64"0.7968700"20.240498 mm
103/128"0.8046875"20.4390625 mm
13/16"0.8125000"20.6375 mm
105/128"0.8203125"20.8359375 mm
53/64"0.8281200"21.034248 mm
107/128"0.8359375"21.2328125 mm
27/32"0.8437500"21.43125 mm
109/128"0.8515625"21.6296875 mm
55/64"0.8593700"21.827998 mm
111/128"0.8671875"22.0265625 mm
7/8"0.8750000"22.225 mm
113/128"0.8828125"22.4234375 mm
57/64"0.8906200"22.621748 mm
115/128"0.8984375"22.8203125 mm
29/32"0.9062500"23.01875 mm
117/128"0.9140625"23.2171875 mm
59/64"0.9218700"23.415498 mm
119/128"0.9296875"23.6140625 mm
15/16"0.9375000"23.8125 mm
121/128"0.9453125"24.0109375 mm
61/64"0.9531200"24.209248 mm
123/128"0.9609375"24.4078125 mm
31/32"0.9687500"24.60625 mm
125/128"0.9765625"24.8046875 mm
63/64"0.9843700"25.002998 mm
127/128"0.9921875"25.2015625 mm
1"1.0000000"25.4 mm


Wire Sizes

InchesMillimeters
0.020"0.508 mm
0.025"0.635 mm
0.028"0.7112 mm
0.030"0.762 mm
0.032"0.8128 mm
0.034"0.8636 mm
0.035"0.889 mm
0.036"0.9144 mm
0.040"1.016 mm
0.041"1.0414 mm
0.045"1.143 mm
0.046"1.1684 mm
0.047"1.1938 mm
0.048"1.2192 mm
0.050"1.27 mm
0.057"1.4478 mm
0.061"1.5494 mm
0.062"1.5748 mm
0.063"1.6002 mm
0.064"1.6256 mm
0.065"1.651 mm
0.068"1.7272 mm
0.072"1.8288 mm
0.078"1.9812 mm
0.080"2.032 mm
0.086"2.1844 mm
0.094"2.3876 mm
0.100"2.54 mm
0.105"2.667 mm
0.123"3.1242 mm