Ring Size Conversion

US, UK, Australia, China, Canada, Japan Comparision Chart

Convert ring sizes between American (US), UK, Australian, Canadian, Chinese and Japanese including with the diameters in inches and millimeters (mm). For all size tables, check size conversions.

For your information, the diameter of a ring is the measure of the distance across the middle inside.

Please note that there is no real international standard for ring sizing. You may need to contact to the manufacturer for exact sizes.

Ring Size Table

US / CANUK / AUSJapanChinaDiameter (inch)Diameter (mm)
0---0.45811.63
¼---0.46611.84
½A--0.47412.04
¾--0.48212.24
1B110.4912.45
--0.49812.65
C--0.50612.85
--0.51413.06
2D220.52213.26
--0.5313.46
E330.53813.67
--0.54613.87
3F440.55414.07
550.56214.27
G--0.5714.48
660.57814.68
4H770.58614.88
--0.59415.09
I880.60215.29
J--0.6115.49
5990.61815.70
K--0.62615.90
10100.63416.10
L--0.64216.31
611110.6516.51
M12120.65816.71
13130.66616.92
N--0.67417.12
714140.68217.32
O--0.6917.53
15150.69817.73
P--0.70617.93
816160.71418.14
Q--0.72218.34
17170.7318.54
R--0.73818.75
918180.74618.95
S--0.75419.15
19190.76219.35
T--0.7719.56
1020200.77819.76
10¼U21210.78619.96
10½22220.79420.17
10¾V--0.80220.37
1123230.8120.57
11¼W--0.81820.78
11½24240.82620.98
11¾X--0.83421.18
1225250.84221.39
12¼Y--0.8521.59
12½Z26260.85821.79
12¾--0.86622.00
13-27270.87422.20
13¼Z1--0.88222.40
13½---0.8922.61
13¾Z2--0.89822.81
14Z3--0.90623.01
14¼---0.91423.22
14½Z4--0.92223.42
14¾---0.9323.62
15---0.93823.83
15¼---0.94624.03
15½---0.95424.23
15¾---0.96224.43
16---0.9724.64