International Ring Size Conversion Chart
Circumference (mm)
Europe / ISO | Diameter (mm) | USA / Canada | UK / Australia | Asia | Switzerland |
|---|
| 44.2 | 14.1 | 3 | F | 4 | 4 | | 44.8 | 14.3 |
| F-1/2 | 5 | 5-1/4 | | 45.5 | 14.5 | 3-1/2 | G |
|
| | 46.1 | 14.7 |
| G-1/2 | 6 | 6-1/2 | | 46.8 | 14.9 | 4 | H | 7 |
| | 47.4 | 15.1 |
| H-1/2 |
| 7-3/4 | | 48.0 | 15.3 | 4-1/2 | I | 8 |
| | 48.7 | 15.5 |
| J |
| 9 | | 49.3 | 15.7 | 5 | J-1/2 | 9 |
| | 50.0 | 15.9 |
| K |
| 10 | | 50.6 | 16.1 | 5-1/2 | K-1/2 | 10 |
| | 51.2 | 16.3 |
| L |
| 11-3/4 | | 51.9 | 16.5 | 6 | L-1/2 | 11 | 12-3/4 | | 52.5 | 16.7 |
| M | 12 |
| | 53.1 | 16.9 | 6-1/2 | M-1/2 | 13 | 14 | | 53.8 | 17.1 |
| N |
|
| | 54.4 | 17.3 | 7 | N-1/2 | 14 | 15-1/4 | | 55.1 | 17.5 |
| O |
|
| | 55.7 | 17.7 | 7-1/2 | O-1/2 | 15 | 16-1/2 | | 56.3 | 17.9 |
| P |
|
| | 57.0 | 18.1 | 8 | P-1/2 | 16 | 17-3/4 | | 57.6 | 18.3 |
| Q |
|
| | 58.3 | 18.5 | 8-1/2 | Q-1/2 | 17 |
| | 58.9 | 18.8 |
| R |
| 19 | | 59.5 | 19.0 | 9 | R-1/2 | 18 |
| | 60.2 | 19.2 |
| S |
| 20-1/4 | | 60.8 | 19.4 | 9-1/2 | S-1/2 | 19 |
| | 61.4 | 19.6 |
| T |
| 21-1/2 | | 62.1 | 19.8 | 10 | T-1/2 | 20 |
| | 62.7 | 20.0 |
| U | 21 |
| | 63.4 | 20.2 | 10-1/2 | U-1/2 | 22 | 22-3/4 | | 64.0 | 20.4 |
| V |
|
| | 64.6 | 20.6 | 11 | V-1/2 | 23 |
| | 65.3 | 20.8 |
| W |
| 25 | | 65.9 | 21.0 | 11-1/2 | W-1/2 | 24 |
| | 66.6 | 21.2 |
| X |
|
| | 67.2 | 21.4 | 12 | X-1/2 | 25 | 27-1/2 | | 67.8 | 21.6 |
| Y |
|
| | 68.5 | 21.8 | 12-1/2 | Z | 26 | 28-3/4 | | 69.1 | 22.0 |
| Z-1/2 |
|
| | 69.7 | 22.2 | 13 |
| 27 |
| | 70.4 | 22.4 |
| Z + 1 |
|
| | 71.0 | 22.6 | 13-1/2 |
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