The following table is meant to assist you to match the different designer size schemes to your usual ring size. Please be advised that rings with a deep band width will need to be slightly larger than your normal rings. Consider this when checking your size. If possible, consult always with the seller to be sure of the product you want to purchase.
International Ring Measurements/Sizes
| US & Can | Size (in) | UK | French | German | Swiss | Japanese |
| 000 | 0.390 | - | - | - | - | - |
| 00 | 0.422 | - | - | - | - | - |
| 0 | 0.454 | - | - | - | - | - |
| 1/2 | 0.462 | A | - | - | - | - |
| 3/4 | 0.471 | A-½ | - | - | - | - |
| 1 | 0.487 | B | - | - | - | 1 |
| 1 1/4 | 0.495 | B-½ | - | - | - | - |
| 1 1/2 | 0.503 | C | - | - | - | - |
| 1 3/4 | 0.511 | C-½ | - | - | - | - |
| 2 | 0.52 | D | 41 1/2 | 13 1/4 | 1 1/2 | 2 |
| 2 1/4 | 0.528 | D-½ | 42 1/8 | 13 1/2 | — | - |
| 2 1/2 | 0.536 | E | 42 3/4 | 13 3/4 | 2 3/4 | 3 |
| 2 3/4 | 0.544 | E-½ | 43 3/8 | - | 3 3/8 | - |
| 3 | 0.553 | F | 44 | 14 | 4 | 4 |
| 3 1/4 | 0.561 | F-½ | 44 5/8 | 14 1/4 | 4 5/8 | - |
| 3 1/2 | 0.569 | G | 45 1/4 | 14 1/2 | 5 1/4 | 5 |
| 3 3/4 | 0.577 | G-½ | 45 7/8 | 14 3/4 | 5 7/8 | 6 |
| 4 | 0.586 | H-½ | 46 1/2 | 15 | 6 1/2 | 7 |
| 4 1/4 | 0.594 | I | 47 1/8 | 15 1/4 | 7 1/8 | - |
| 4 1/2 | 0.602 | I-½ | 47 3/4 | 15 1/2 | 7 3/4 | 8 |
| 4 3/4 | 0.61 | J | 48 3/8 | - | 8 3/8 | - |
| 5 | 0.619 | J-½ | 49 | 15 3/4 | 9 | 9 |
| 5 1/4 | 0.627 | K | 49 5/8 | 16 | 9 5/8 | - |
| 5 1/2 | 0.635 | K-½ | 50 1/4 | 16 1/4 | 10 1/4 | 10 |
| 5 3/4 | 0.643 | L | 50 7/8 | - | 10 7/8 | 11 |
| 6 | 0.652 | L-½ | 51 1/2 | 16 1/2 | 11 1/2 | 12 |
| 6 1/4 | 0.66 | M | 52 1/8 | 16 3/4 | 12 1/8 | - |
| 6 1/2 | 0.668 | M-½ | 52 3/4 | 17 | 12 3/4 | 13 |
| 6 3/4 | 0.676 | N | 53 3/8 | - | 13 3/8 | - |
| 7 | 0.685 | O | 54 | 17 1/4 | 14 | 14 |
| 7 1/4 | 0.693 | O-½ | 54 5/8 | 17 1/2 | 14 5/8 | - |
| 7 1/2 | 0.701 | P | 55 1/4 | 17 3/4 | 15 1/4 | 15 |
| 7 3/4 | 0.709 | P-½ | 55 7/8 | - | 15 7/8 | - |
| 8 | 0.717 | Q | 56 1/2 | 18 | 16 1/2 | 16 |
| 8 1/4 | 0.726 | Q-½ | 57 1/8 | 18 1/4 | 17 1/8 | - |
| 8 1/2 | 0.734 | R | 57 3/4 | 18 1/2 | 17 3/4 | 17 |
| 8 3/4 | 0.742 | R-½ | 58 3/8 | 18 3/4 | 18 3/8 | - |
| 9 | 0.75 | S | 59 | 19 | 19 | 18 |
| 9 1/4 | 0.759 | S-½ | 59 5/8 | 19 1/4 | 19 5/8 | - |
| 9 1/2 | 0.767 | - | 60 1/4 | 19 1/2 | 20 1/4 | 19 |
| 9 3/4 | 0.775 | T | 60 7/8 | 19 3/4 | 20 7/8 | - |
| 10 | 0.783 | T-½ | 61 1/2 | 20 | 21 1/2 | 20 |
| 10 1/4 | 0.792 | U | 62 1/8 | 20 1/4 | 22 1/8 | 21 |
| 10 1/2 | 0.8 | U-½ | 62 3/4 | 20 1/2 | 22 3/4 | 22 |
| 10 3/4 | 0.808 | V | 63 3/8 | - | 23 3/8 | - |
| 11 | 0.816 | V-½ | 64 | 20 3/4 | 24 | 23 |
| 11 1/4 | 0.825 | W | 64 5/8 | - | 24 5/8 | - |
| 11 1/2 | 0.833 | W-½ | 65 1/4 | 21 | 25 1/4 | 24 |
| 11 3/4 | 0.841 | X | 65 7/8 | - | 25 7/8 | - |
| 12 | 0.849 | Y | 66 1/2 | 21 1/4 | 26 1/2 | 25 |
| 12 1/4 | 0.858 | Y-½ | 67 1/8 | 21 1/2 | 27 1/8 | - |
| 12 1/2 | 0.866 | Z | 67 3/4 | 21 3/4 | 27 3/4 | 26 |
| 12 3/4 | 0.874 | Z-½ | 68 3/8 | - | 28 3/8 | - |
| 13 | 0.882 | - | 69 | 22 | 29 | 27 |
