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 and circumferences in inches and millimeters (mm).

For your information, circumference of a ring is the measure of the length around the circle. 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.

For other types of size conversions, please go back to Size Converter .

Ring Size Table

US / CanadaUK / AustraliaJapanChinaDiameter (inch)Diameter (mm)Circum ference (inch)Circum ference (mm)
0---0.45811.631.4436.5
¼---0.46611.841.4637.2
½A--0.47412.041.4937.8
¾--0.48212.241.5138.5
1B110.4912.451.5439.1
--0.49812.651.5639.7
C--0.50612.851.5940.4
--0.51413.061.6141.0
2D220.52213.261.6441.7
--0.5313.461.6742.3
E330.53813.671.6942.9
--0.54613.871.7243.6
3F440.55414.071.7444.2
550.56214.271.7744.8
G--0.5714.481.7945.5
660.57814.681.8246.1
4H770.58614.881.8446.8
--0.59415.091.8747.4
I880.60215.291.8948.0
J--0.6115.491.9248.7
5990.61815.701.9449.3
K--0.62615.901.9750.0
10100.63416.101.9950.6
L--0.64216.312.0251.2
611110.6516.512.0451.9
M12120.65816.712.0752.5
13130.66616.922.0953.1
N--0.67417.122.1253.8
714140.68217.322.1454.4
O--0.6917.532.1755.1
15150.69817.732.1955.7
P--0.70617.932.2256.3
816160.71418.142.2457.0
Q--0.72218.342.2757.6
17170.7318.542.2958.3
R--0.73818.752.3258.9
918180.74618.952.3459.5
S--0.75419.152.3760.2
19190.76219.352.3960.8
T--0.7719.562.4261.4
1020200.77819.762.4462.1
10¼U21210.78619.962.4762.7
10½22220.79420.172.4963.4
10¾V--0.80220.372.5264.0
1123230.8120.572.5464.6
11¼W--0.81820.782.5765.3
11½24240.82620.982.5965.9
11¾X--0.83421.182.6266.6
1225250.84221.392.6567.2
12¼Y--0.8521.592.6767.8
12½Z26260.85821.792.7068.5
12¾--0.86622.002.7269.1
13-27270.87422.202.7569.7
13¼Z1--0.88222.402.7770.4
13½---0.8922.612.8071.0
13¾Z2--0.89822.812.8271.7
14Z3--0.90623.012.8572.3
14¼---0.91423.222.8772.9
14½Z4--0.92223.422.9073.6
14¾---0.9323.622.9274.2
15---0.93823.832.9574.8
15¼---0.94624.032.9775.5
15½---0.95424.233.0076.1
15¾---0.96224.433.0276.8
16---0.9724.643.0577.4