Ring Size Chart

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