Maison Mugen uses US measurements for our rings. Measure or determine your ring size according to your country’s standard. Then use the International Ring Size Chart to convert to the corresponding US ring size to place your order.  
Circumference (mm) Diameter (mm)  UK, EU US CN SG, JP HK
46.8 14.9 H 4 8 7 9
47.4 15.1 H1/2   9    
48 15.3 I  41/2   8 10
48.7 15.5 J         
49.3 15.7 J1/2 5 10 9 11
50 15.9 K        
50.6 16.1 K1/2 5 1/2 11 10 12
51.2 16.3 L        
51.9 16.5 L1/2 6 12 11 13
52.5 16.7 M   13 12  
53.1 16.9 M1/2 6 1/2   13 14.5
53.8 17.1 N   14    
54.4 17.3 N1/2 7   14 16
55.1 17.5 O   15    
55.7 17.7 O1/2 7 1/2   15 17
56.3 17.9 P   16    
57 18.1 P1/2 8 17 16  
57.2 18.2          
57.6 18.3 Q        
58.3 18.5 Q1/2 81/2 18 17 19
58.9 18.8 R        
59.5 19 R1/2 9 19 18 20.5
60.2 19.2 S   20    
60.8 19.4 S1/2 9 1/2   19 22
61.4 19.6 T   21    
62.1 19.8 T1/2  10   20 23
62.7 20 U   22 21  
63.4 20.2 U1/2  10 1/2   22 24
64 20.4 V   23    
64.6 20.6 V1/2 11   23 25
65.3 20.8 W   24    
65.9 21 W1/2  11 1/2 25 24 26
66.6 21.2 X        
67.2 21.4 X 1/2 12 26 25 27.75