International Ring Size Conversion
| USA, Canada | UK, Australia, Ireland, New Zealand | Japan, India, China, South Africa | Spain, Italy, Netherlands, Switzerland | Inside-Diameter & Circumference (mm) |
|---|---|---|---|---|
| 4 | H | 7 | 6.75 | 14.88 & 46.80 |
| 4.25 | H.5 | 7.5 | 15.09 & 47.40 | |
| 4.5 | I | 8 | 8 | 15.29 & 48.00 |
| 4.75 | J | 8.75 | 15.49 & 48.70 | |
| 5 | J 1/2 | 9 | 9.25 | 15.70 & 49.30 |
| 5.25 | K | 10 | 15.90 & 50.00 | |
| 5.5 | K 1/2 | 10 | 10.5 | 16.10 & 50.60 |
| 5.75 | L | 11.25 | 16.31 & 51.20 | |
| 6 | L 1/2 | 11 | 11.75 | 16.51 & 51.90 |
| 6.25 | M | 12 | 12.5 | 16.71 & 52.50 |
| 6.5 | M 1/2 | 13 | 13.25 | 16.92 & 53.10 |
| 6.75 | N | 13.75 | 17.12 & 53.80 | |
| 7 | N 1/2 | 14 | 14.5 | 17.32 & 54.40 |
| 7.25 | O | 15 | 15 | 17.53 & 55.10 |
| 7.5 | O 1/2 | 15 | 15.75 | 17.73 & 55.70 |
| 7.75 | P | 16.25 | 17.93 & 56.30 | |
| 8 | P 1/2 | 16 | 17 | 18.14 & 57.00 |
| 8.25 | Q | 17.5 | 18.34 & 57.60 | |
| 8.5 | Q 1/2 | 17 | 18.25 | 18.54 & 58.30 |
| 8.75 | R | 19 | 18.75 & 58.90 | |
| 9 | R 1/2 | 18 | 19.5 | 18.95 & 59.50 |
| 9.25 | S | 20.25 | 19.15 & 60.20 | |
| 9.5 | S 1/2 | 19 | 20.75 | 19.35 & 60.80 |
| 9.75 | T | 21.5 | 19.56 & 61.40 | |
| 10 | T 1/2 | 20 | 22 | 19.76 & 62.10 |
| 10.25 | U | 21 | 22.75 | 19.96 & 62.70 |
| 10.5 | U 1/2 | 22 | 23.25 | 20.17 & 63.40 |
| 10.75 | V | 24 | 20.37 & 64.00 | |
| 11 | V 1/2 | 23 | 24.75 | 20.57 & 64.60 |
| 11.25 | W | 25.25 | 20.78 & 65.30 | |
| 11.5 | W 1/2 | 24 | 26 | 20.98 & 65.90 |
| 11.75 | X | 26.5 | 21.18 & 66.60 | |
| 12 | X 1/2 | 25 | 27.25 | 21.39 & 67.20 |
| 12.25 | Y | 27.75 | 21.59 & 67.80 | |
| 12.5 | Z | 26 | 28.5 | 21.79 & 68.50 |
| 12.75 | Z 1/2 | 29 | 22.00 & 69.10 | |
| 13 | Z1 | 27 | 29.75 | 22.20 & 69.70 |
| 13.25 | Z2 | 30.5 | 22.40 & 70.40 | |
| 13.5 | Z3 | 31 | 22.61 & 71.00 | |
| 13.75 | Z4 | 31.75 | 22.81 & 71.70 | |
| 14 | Z5 | 32.25 | 23.01 & 72.30 | |
| 14.25 | 33 | 23.22 & 72.90 | ||
| 14.5 | Z6 | 33.5 | 23.42 & 73.60 | |
| 14.75 | 34.25 | 23.62 & 74.20 | ||
| 15 | 34.75 | 24.23 & 76.10 |
