US Standard (Also Canada) | Diameter in Inches | British Equivalent | French Equivalent | German Equivalent | Swiss Equivalent | Japanese Equivalent |
---|---|---|---|---|---|---|
0 | .454 | – | – | – | – | – |
1/2 | – | A | – | – | – | – |
1 | .487 | B | – | – | – | 1 |
1 1/2 | .503 | C | – | – | – | – |
2 | .520 | D | 41 ½ | 13 ¼ | 1 ½ | 2 |
2 1/2 | .536 | E | 42 ¾ | 13 ¾ | 2 ¾ | 3 |
3 | .553 | F | 44 | 14 | 4 | 4 |
3 3/8 | – | G | 45 ½ | – | 5 ½ | 5 |
3 1/2 | .569 | – | – | 14 ½ | – | – |
3 3/4 | – | H | 46 ½ | – | 6 ½ | – |
4 | .585 | H ½ | – | 15 | – | 7 |
4 1/4 | – | I | 47 ¾ | – | 7 ¾ | – |
4 7/8 | – | J | 49 | – | 9 | – |
5 | .618 | J ½ | – | 15 ¾ | – | 9 |
5 1/8 | – | K | 50 | – | 10 | – |
5 1/2 | .634 | L | 51 ¾ | 16 | 11 ¾ | – |
6 | .650 | M | 52 ¾ | 16 ½ | 12 ¾ | 12 |
6 1/2 | .666 | N | 54 | 17 | 14 | 13 |
7 | .683 | O | 55 ¼ | 17 ¼ | 15 ¼ | 14 |
7 1/4 | .699 | P | 56 ½ | 17 ¾ | 16 ½ | 15 |
8 | .716 | Q | 57 ¾ | 18 | 17 ¾ | 16 |
8 1/2 | .732 | – | – | 18 ½ | – | 17 |
8 5/8 | – | R | 59 | – | 19 | – |
9 | .748 | – | – | 19 | – | 18 |
9 1/8 | – | S | 60 ¼ | – | 20 ¼ | – |
9 1/4 | .764 | – | – | 19 ½ | – | 19 |
9 5/8 | – | T | 61 ½ | – | 21 ½ | – |
10 | .781 | T ½ | – | 20 | – | 20 |
10 1/4 | – | U | 62 ¾ | – | 22 ¾ | 21 |
10 1/2 | .797 | U ½ | – | 20 ¼ | – | 22 |
10 5/8 | – | V | 63 ¾ | – | 23 ¾ | – |
11 | .814 | V ½ | – | 20 ¾ | – | 23 |
11 1/8 | – | W | 65 | – | 25 | – |
11 1/2 | .830 | – | – | 21 | – | 24 |
11 5/8 | – | X | 66 ¼ | – | 26 ¼ | – |
12 | .846 | Y | 67 ½ | 21 ¼ | 27 ½ | 25 |
12 1/2 | .862 | Z | 68 ¾ | 21 ¾ | 28 ¾ | 26 |
13 | .879 | – | – | 22 | – | 27 |
Ring Size Comparison Chart
Compliments of The International Gem Society