rings size conversion chart


 

US SIZE UK SIZE INSIDE DIA IN INSIDE DIA MM INSIDE CIRC IN INSIDE CIRC MM
1/2 A 0.474 12.0 1.488 37.8
3/4 A 1/2 0.482 12.2 1.513 38.4
1 B 0.490 12.4 1.539 39.1
1 1/4 B 1/2 0.498 12.6 1.564 39.7
1 1/2 C 0.506 12.9 1.589 40.4
1 3/4 C 1/2 0.514 13.1 1.614 41.0
2 D 0.522 13.3 1.639 41.6
2 1/4 D 1/2 0.530 13.5 1.664 42.3
2 1/2 E 0.538 13.7 1.689 42.9
2 3/4 E 1/2 0.546 13.9 1.714 43.5
3 F 0.554 14.1 1.740 44.2
3 1/4 F 1/2 0.562 14.3 1.765 44.8
3 1/2 G 0.570 14.5 1.790 45.5
3 3/4 G 1/2 0.578 14.7 1.815 46.1
4 H 0.586 14.9 1.840 46.7
4 1/4 H 1/2 0.594 15.1 1.865 47.4
4 1/2 I 0.602 15.3 1.890 48.0
4 3/4 J 0.610 15.5 1.915 48.7
5 J 1/2 0.618 15.7 1.941 49.3
5 1/4 K 0.626 15.9 1.966 49.9
5 1/2 K 1/2 0.634 16.1 1.991 50.6
5 3/4 L 0.642 16.3 2.016 51.2
6 L 1/2 0.650 16.5 2.041 51.8
6 1/4 M 0.658 16.7 2.066 52.5
6 1/2 M 1/2 0.666 16.9 2.091 53.1
6 3/4 N 0.674 17.1 2.116 53.8
7 N 1/2 0.682 17.3 2.141 54.4
7 1/4 O 0.690 17.5 2.167 55.0
7 1/2 O 1/2 0.698 17.7 2.192 55.7
7 3/4 P 0.706 17.9 2.217 56.3
8 P 1/2 0.714 18.1 2.242 56.9
8 1/4 Q 0.722 18.3 2.267 57.6
8 1/2 Q 1/2 0.730 18.5 2.292 58.2
8 3/4 R 0.738 18.7 2.317 58.9
9 R 1/2 0.746 18.9 2.342 59.5
9 1/4 S 0.754 19.2 2.368 60.1
9 1/2 S 1/2 0.762 19.4 2.393 60.8
9 3/4 T 0.770 19.6 2.418 61.4
10 T 1/2 0.778 19.8 2.443 62.1
10 1/4 U 0.786 20.0 2.468 62.7
10 1/2 U 1/2 0.794 20.2 2.493 63.3
10 3/4 V 0.802 20.4 2.518 64.0
11 V 1/2 0.810 20.6 2.543 64.6
11 1/4 W 0.818 20.8 2.569 65.2
11 1/2 W 1/2 0.826 21.0 2.594 65.9
11 3/4 X 0.834 21.2 2.619 66.5
12 X 1/2 0.842 21.4 2.644 67.2
12 1/4 Y 0.850 21.6 2.669 67.8
12 1/2 Z 0.858 21.8 2.694 68.4
12 3/4 Z 1/2 0.866 22.0 2.719 69.1
13   0.874 22.2 2.744 69.7
13 1/4 Z1 0.882 22.4 2.769 70.3
13 1/2   0.890 22.6 2.795 71.0
13 3/4 Z2 0.898 22.8 2.820 71.6
14 Z3 0.906 23.0 2.845 72.3
14 1/4   0.914 23.2 2.870 72.9
14 1/2 Z4 0.922 23.4 2.895 73.5
14 3/4   0.930 23.6 2.920 74.2
15   0.938 23.8 2.945 74.8
15 1/4   0.946 24.0 2.970 75.4
15 1/2   0.954 24.2 2.996 76.1
15 3/4   0.962 24.4 3.021 76.7
16   0.970 24.6 3.046 77.4
16 1/4   0.978 24.8 3.071 78.0
16 1/2   0.986 25.0 3.096 78.6
16 3/4   0.994 25.2 3.121 79.3
17   1.002 25.5 3.146 79.9
17 1/4   1.010 25.7 3.171 80.6
17 1/2   1.018 25.9 3.197 81.2
17 3/4   1.026 26.1 3.222 81.8
18   1.034 26.3 3.247 82.5
18 1/4   1.042 26.5 3.272 83.1
18 1/2   1.050 26.7 3.297 83.7
18 3/4   1.058 26.9 3.322 84.4
19   1.066 27.1 3.347 85.0
19 1/4   1.074 27.3 3.372 85.7
19 1/2   1.082 27.5 3.397 86.3
19 3/4   1.090 27.7 3.423 86.9
20   1.098 27.9 3.448 87.6
20 1/4   1.106 28.1 3.473 88.2
20 1/2   1.114 28.3 3.498 88.8
20 3/4   1.122 28.5 3.523 89.5
21   1.130 28.7 3.548 90.1
21 1/4   1.138 28.9 3.573 90.8
21 1/2   1.146 29.1 3.598 91.4
21 3/4   1.154 29.3 3.624 92.0
22   1.162 29.5 3.649 92.7
22 1/4   1.170 29.7 3.674 93.3
22 1/2   1.178 29.9 3.699 94.0
22 3/4   1.186 30.1 3.724 94.6
23   1.194 30.3 3.749 95.2
23 1/4   1.202 30.5 3.774 95.9
23 1/2   1.210 30.7 3.799 96.5
23 3/4   1.218 30.9 3.825 97.1
24   1.226 31.1 3.850 97.8
24 1/4   1.234 31.3 3.875 98.4
24 1/2   1.242 31.5 3.900 99.1
24 3/4   1.250 31.8 3.925 99.7
25   1.258 32.0 3.950 100.3
25 1/4   1.266 32.2 3.975 101.0
25 1/2   1.274 32.4 4.000 101.6
25 3/4   1.282 32.6 4.025 102.2
26   1.290 32.8 4.051 102.9