Rings size chart - centimetres
| Size: | Inside diameter: | Inside circumference: | USA/Canada sizing | UK/Ireland/Australia sizing |
|---|---|---|---|---|
| (mm) | (mm) | |||
| 11,25 | 16,3 | 51,10 | 5 3/4 | L |
| 11,75 | 16,51 | 51,9 | 6 | L 1/2 |
| 12 1/2 | 16,7 | 52,5 | 6 1/4 | M |
| 13 | 16.9 | 53 | 6 1/2 | M 1/2 |
| 14 1/3 | 17,3 | 54,4 | 7 | N 1/2 |
| 16,25 | 17,93 | 56,3 | 7 3/4 | P |
| 17 1/2 | 18,3 | 57,5 | 8 1/3 | Q |
| 18 | 18.5 | 58 | 8 1/2 | Q 1/2 |
| 18,8 | 18,7 | 58,8 | 8 3/4 | R |
| 19,5 | 18,95 | 59,5 | 9 | R 1/2 |
| 20 | 19,1 | 60 | 9 1/4 | S |
| 21 | 19,4 | 61 | 9 1/2 | S 3/4 |
| 22 | 19,76 | 62 | 9 7/8 | T 1/2 |
| 22 1/2 | 19,9 | 62,5 | 10 1/4 | U |
| 23 | 20,1 | 63,1 | 10 3/8 | U 1/2 |
| 23 3/4 | 20,3 | 63,8 | 10 5/8 | V |
| 24 1/4 | 20,5 | 64,4 | 10 7/8 | V 1/2 |
| 24 3/4 | 20,6 | 64,7 | 11 | V 3/4 |
| 26 | 21 | 66 | 11 1/2 | W 3/4 |
| 26 1/4 | 21,1 | 66,2 | 11 5/8 | X |
| 27 | 21,30 | 67 | 11 7/8 | X 1/2 |
| 27 1/8 | 21,4 | 67,2 | 12 | X 3/4 |
| 28 3/4 | 21,9 | 68,7 | 12 5/8 | Z |
| 29 | 22 | 69 | 12 6/8 | Z 1/4 |
| 29 1/3 | 22,10 | 69,4 | 12 7/8 | Z 1/2 |
| 29,5 | 22,5 | 70,5 | 13 3/8 | Z + 1/2 |
| Z++ | 22,7 | 71,3 | 13 1/2 | Z++ |
| 32,5 | 22,9 | 72 | 13 7/8 | Z ++ 1/2 |
| 34,75 | 23,1 | 72,5 | 14 1/4 | Z+++ |
| Z+3 1/2 | 23,2 | 73 | 14 1/4 | Z+3 1/2 |
| Z++++ | 23,5 | 73,9 | 14 5/8 | Z++++ |
| Z++++.9 | 23,83 | Z++++.9 |