This chart shows ring sizes according to different sizing systems, with the corresponding diameter and circumference measurements in millimeters and inches. Please note that rings measurements are always taken from the inside of the band (since ring thickness can vary).
There is now an international standard for ring sizing, ISO 8653:2016, and this standard has been adopted by most countries in continental Europe. The ISO standard corresponds to the inside circumference in millimeters. Ring sizing systems that pre-date the ISO standard are still widely used in North America, the UK and Australia, and we have included them in this chart. There are also a number of other systems in use around the world.
Inside Diameter |
Inside Circumference |
Ring Sizes |
||||
MM | Inches | MM | Inches | USA & Canada |
Europe | UK & Aus. |
11.63 | 0.458 | 36.5 | 1.44 | 0 | 36 |
|
11.84 | 0.466 | 37.2 | 1.46 | 1/4 | 37 | |
12.04 | 0.474 | 37.8 | 1.49 |
1/2 | A |
|
12.24 | 0.482 | 38.5 | 1.51 |
3/4 | 38 | A 1/2 |
12.45 | 0.490 | 39.1 | 1.54 |
1 | 39 |
B |
12.65 | 0.498 | 39.7 | 1.56 | 1 1/4 |
B 1/2 | |
12.85 | 0.506 | 40.4 | 1.59 | 1 1/2 |
C |
|
13.06 | 0.514 | 41.0 | 1.61 | 1 3/4 | 41 |
C 1/2 |
13.26 | 0.522 | 41.7 | 1.64 | 2 | D | |
13.46 | 0.530 |
42.3 | 1.67 | 2 1/4 | 42 | D 1/2 |
13.67 | 0.538 | 42.9 | 1.69 |
2 1/2 | 43 | E |
13.87 | 0.546 |
43.6 | 1.72 |
2 3/4 | E 1/2 |
|
14.07 | 0.554 | 44.2 | 1.74 | 3 | 44 |
F |
14.27 | 0.562 | 44.8 | 1.77 | 3 1/4 | 45 | F 1/2 |
14.48 | 0.570 | 45.5 | 1.79 | 3 1/2 | G |
|
14.68 | 0.578 | 46.1 | 1.82 |
3 3/4 | G 1/2 |
|
14.88 | 0.586 |
46.8 | 1.84 | 4 | 46 | H |
15.09 | 0.594 | 47.4 | 1.87 | 4 1/4 | 47 | H 1/2 |
15.29 | 0.602 | 48.0 | 1.89 | 4 1/2 | 48 | I |
15.49 | 0.610 | 48.7 | 1.92 |
4 3/4 | J |
|
15.70 | 0.618 | 49.3 | 1.94 | 5 | 49 | J 1/2 |
15.90 | 0.626 | 50.0 | 1.97 | 5 1/4 | 50 | K |
16.10 | 0.634 | 50.6 | 1.99 | 5 1/2 | K 1/2 | |
16.31 | 0.642 | 51.2 | 2.02 | 5 3/4 | 51 | L |
16.51 | 0.650 | 51.9 | 2.04 | 6 | L 1/2 |
|
16.71 | 0.658 | 52.5 | 2.07 | 6 1/4 | 52 | M |
16.92 | 0.666 |
53.1 | 2.09 |
6 1/2 | 53 |
M 1/2 |
17.12 | 0.674 | 53.8 | 2.12 | 6 3/4 | 54 | N |
17.32 | 0.682 |
54.4 | 2.14 | 7 | 55 |
N 1/2 |
17.53 | 0.690 | 55.1 | 2.17 |
7 1/4 |
O | |
17.73 | 0.698 | 55.7 | 2.19 | 7 1/2 |
56 | O 1/2 |
17.93 | 0.706 | 56.3 | 2.22 |
7 3/4 | P | |
18.14 | 0.714 |
57.0 | 2.24 | 8 | 57 | P 1/2 |
18.34 | 0.722 |
57.6 | 2.27 |
8 1/4 | Q |
|
18.54 | 0.730 |
58.3 | 2.29 | 8 1/2 | 58 | Q 1/2 |
18.75 | 0.738 |
58.9 | 2.32 | 8 3/4 | R |
|
18.95 | 0.746 | 59.5 | 2.34 |
9 | 59 |
R 1/2 |
19.15 | 0.754 | 60.2 | 2.37 |
9 1/4 | 60 |
S |
19.35 | 0.762 |
60.8 | 2.39 | 9 1/2 | 61 | S 1/2 |
19.56 | 0.770 |
61.4 | 2.42 | 9 3/4 | T |
|
19.76 | 0.778 | 62.1 | 2.44 | 10 | 62 | T 1/2 |
19.96 | 0.786 | 62.7 | 2.47 | 10 1/4 | U | |
20.17 | 0.794 | 63.4 | 2.49 |
10 1/2 | 63 |
U 1/2 |
20.37 | 0.802 |
64.0 | 2.52 | 10 3/4 | 64 | V |
20.57 | 0.810 | 64.6 | 2.54 | 11 | 65 |
V 1/2 |
20.78 | 0.818 | 65.3 | 2.57 |
11 1/4 | W | |
20.98 | 0.826 | 65.9 | 2.59 | 11 1/2 |
66 |
W 1/2 |
21.18 | 0.834 | 66.6 | 2.62 |
11 3/4 | X | |
21.39 | 0.842 | 67.2 | 2.65 |
12 | 67 |
X 1/2 |
21.59 | 0.850 | 67.8 | 2.67 |
12 1/4 | Y | |
21.79 | 0.858 |
68.5 | 2.70 | 12 1/2 | 68 | Z |
22.00 | 0.866 | 69.1 | 2.72 | 12 3/4 | 69 |
Z 1/2 |
22.20 | 0.874 | 69.7 | 2.75 | 13 | ||
22.40 | 0.882 |
70.4 | 2.77 |
13 1/4 | 70 | Z1 |
22.61 | 0.890 |
71.0 | 2.80 | 13 1/2 | 71 |
|
22.81 | 0.898 | 71.7 | 2.82 | 13 3/4 |
Z2 | |
23.01 | 0.906 | 72.3 | 2.85 | 14 | 72 |
Z3 |
23.22 | 0.914 | 72.9 | 2.87 |
14 1/4 |
73 |
|
23.42 | 0.922 | 73.6 | 2.90 | 14 1/2 |
Z4 |
|
23.62 | 0.930 | 74.2 | 2.92 | 14 3/4 |
74 |
|
23.83 | 0.938 | 74.8 | 2.95 |
15 | 75 | |
24.03 | 0.946 | 75.5 | 2.97 |
15 1/4 | ||
24.23 | 0.954 | 76.1 | 3.00 | 15 1/2 | 76 |
|
24.43 | 0.962 | 76.8 | 3.02 | 15 3/4 | ||
24.64 | 0.970 | 77.4 | 3.05 |
16 | 77 |