All rings are specified in standard US sizes. Please use the table below to determine your size. Diameter (mm) Circumference (mm) US UK French/ German Italian 15.1 47.44 4 H½ 47.5 7.5 15.3 48.07 4.25 I 48 8 15.5 48.69 4.5 I½ 48.5 8.5 15.7 49.32 4.75 J 49.5 9.5 15.9 49.95 5 J½ 50 10 16.1 50.58 5.25 K 50.5 10.5 16.3 51.21 5.5 K½ 51 11 16.5 51.84 5.75 L 52 12 16.7 52.46 6 L½ 52.5 12.5 16.9 53.09 6.25 M 53 13 17.1 53.72 6.5 M½ 54 14 17.3 54.35 6.75 N 54.5 14.5 17.5 54.98 7 N½ 55 15 17.7 55.61 7.25 O 55.75 15.75 17.9 56.23 7.5 O½ 56.25 16.25 18.1 56.86 7.75 P 57 17 18.3 57.49 8 P½ 57.25 17.25 18.5 58.12 8.25 Q 58 18 18.7 58.75 8.5 Q½ 58.5 18.5 18.9 59.38 8.75 R 59.5 19.5 19.1 60 9 R½ 60 20 19.3 60.63 9.25 S 60.5 20.5 19.5 61.26 9.5 S½ 61.25 21.25 19.7 61.89 9.75 T 62 22 19.9 62.52 10 T½ 62.5 22.5 20.1 63.15 10.5 U 63 23 20.3 63.77 10.5 U½ 64 24 20.5 64.4 10.75 V 64.25 24.25 20.7 65.03 11 V½ 65 25 How to measure ring size: 1. Get a piece of string or cut up a thin piece of paper and wrap it around your finger firmly. (make sure the paper/string sits very firm on your finger, how you would want the ring to fit; that means it should not be loose and not extremely tight) 2. Mark the string or piece of paper to get the circumference (in mm) 3. Lay the string or paper down against a ruler to measure the circumference (in mm) 4. Please use the table above to measure your circumference (in mm) against the US sizing column (All rings are specified in standard US sizes.)5. Please choose the ring size that is closest to your circumference if you are in-between sizes. If you have an existing ringAlternatively, please measure the internal diameter if your current ring and use the chart to measure inside diameter against US sizing. Tips: Please measure your finger when they are warm as cold fingers will measure smaller.