International Ring Size Conversion

We also recommend that if you are in doubt about your ring size, please visit a local jeweler and have them measure your ring size. 
ner Diameter 
(mm)
  US and Canada
Ring Size
Australia,
UK, Ireland
Japan,
China
11.63 0    
11.84 .25    
12.04 .50 A  
12.24   .75 A 1/2  
12.45   1.0 B 1
12.65   1.25 B 1/2  
12.85   1.50 C  
13.06   1.75 C 1/2  
13.26   2.00 D 2
13.46   2.25 D 1/2  
13.67   2.50 E 3
13.87   2.75 E 1/2  
14.07   3.00 F 4
14.27   3.25 F 1/2 5
14.48   3.50 G  
14.68   3.75 G 1/2 6
14.88   4.00 H 7
15.00   4.25 H 1/2  
15.29   4.50 I 8
15.49   4.75 J  
15.70   5.00 J 1/2 9
15.90   5.25 K  
16.10   5.50 K 1/2 10
16.31   5.75 L  
16.51   6.00 L 1/2 11
16.71   6.25 M 12
16.92   6.50 M 1/2 13
17.12   6.75 N  
17.32   7.00 N 1/2 14
17.53   7.25 O  
17.73   7.50 O 1/2 15
17.93   7.75 P  
18.14   8.00 P 1/2 16
18.34   8.25 Q  
18.54   8.50 Q 1/2 17
18.75   8.75 R  
18.95   9.00 R 1/2 18
19.15   9.25 S  
19.35   9.50 S 1/2 19
19.56   9.75 T  
19.76   10.00 T 1/2 20
19.96   10.25 U 21
20.17   10.50 U 1/2 22
20.37   10.75 V  
20.57   11.00 V 1/2 23
20.78   11.25 W  
20.98   11.50 W 1/2 24
21.18   11.75 X  
21.39   12.00 X 1/2 25
21.59   12.25 Y  
21.79   12.50 Z 26
22.00   12.75 Z 1/2  
22.20   13.00   27
22.40   13.25 Z1  
22.61   13.50    
22.81   13.75 Z2  
23.01   14.00 Z3  
23.22   14.25    
23.42   14.50 Z4  
23.62   14.75    
23.83   15.00    
24.03   15.25    
24.23   15.50    
24.43   15.75    
24.64   16.00