International Ring Size Conversion Chart

International Ring Size Conversion Chart

SizesInside DiameterInside Circumference
US & CAUK&AUMMInchesMMInches
9.0R 3/418.90.7559.32.35
9.5S 3/419.40.7661.02.40
10.0T 1/219.80.7862.32.45
10.5U 1/220.20.8063.52.50
11.0V 1/220.70.8165.02.56
11.5W 3/421.00.8366.22.61
12.0Y21.50.8567.52.66
12.5Z21.90.8668.82.71
13.0Z+122.330.8870.22.76