Ring Size Conversion Chart item

There is no substitute for having your finger measured professionally, but it's not an exact science. Our fingers change in size from morning to evening, month to month and even Winter to Summer. The following chart is helpful to see how the sizes are compiled. UK: Diameter mm Circumference mm American

K 15.9 49.95 5.25 L 16.3 51.24 5.75
M 16.7 52.46 6.25
N 17.1 53.72 6.75
O 17.5 54.98 7
P 17.9 56.23 7.5
Q 18.3 57.49 8
R 18.7 58.75 8.5
S 19.1 60.00 9
T 19.5 61.26 9.5
U 19.9 62.52 10
V 20.3 63.77 10.5
W 20.7 65.00 11
X 21.1 66.29 11.5
Y 21.5 67.51 12

To calculate: American size= (diameter-11.54)/(0.83) Japanese size= (diameter-12.67)*3 European size= circumference-40 Note：The “dia.” and “Circumference” here are the inside diameter and perimeter of the rings http://www.diy-supplies.net