Ring size conversion chart
INSIDE DIAMETER | INSIDE CIRCUMFERENCE | SIZES | |||||
---|---|---|---|---|---|---|---|
MM | INCHES | MM | INCHES | BRITISH & AUSTRALIAN | US & CANADA | FRENCH & RUSSIAN | JAPANESE |
15.70 | 0.618 | 49.32 | 1.94 | J 1/2 | 5 | - | 9 |
15.80 | 0.622 | 49.64 | 1.95 | K | 5 1/8 | 50 | - |
15.90 | 0.626 | 49.95 | 1.97 | K 1/4 | 5 1/4 | - | - |
16.00 | 0.630 | 50.27 | 1.98 | K 1/2 | 5 3/8 | - | 10 |
16.10 | 0.634 | 50.58 | 1.99 | L | 5 1/2 | 51 3/4 | - |
16.30 | 0.642 | 51.24 | 2.02 | L 1/4 | 5 3/4 | - | - |
16.41 | 0.646 | 51.55 | 2.03 | L 1/2 | 5 7/8 | 52 | - |
16.51 | 0.650 | 51.87 | 2.05 | M | 6 | - | 12 |
16.71 | 0.658 | 52.50 | 2.07 | M 1/2 | 6 1/4 | 53 | - |
16.92 | 0.666 | 53.16 | 2.09 | N | 6 1/2 | 54 | 13 |
17.13 | 0.674 | 53.82 | 2.12 | N 1/2 | 6 3/4 | - | - |
17.35 | 0.683 | 54.51 | 2.15 | O | 7 | 55 | 14 |
17.45 | 0.687 | 54.82 | 2.16 | O 1/2 | 7 1/4 | - | - |
17.75 | 0.699 | 55.76 | 2.20 | P | 7 1/2 | 56 | 15 |
17.97 | 0.707 | 56.45 | 2.22 | P 1/2 | 7 3/4 | - | - |
18.19 | 0.716 | 57.15 | 2.25 | Q | 8 | 57 | 16 |
18.35 | 0.722 | 57.65 | 2.27 | Q 1/4 | 8 1/4 | 58 | - |
18.53 | 0.729 | 58.21 | 2.29 | Q 3/4 | 8 1/2 | - | 17 |
18.61 | 0.733 | 58.47 | 2.30 | R | 8 5/8 | 59 | - |
18.69 | 0.736 | 58.72 | 2.31 | R 1/4 | 8 3/4 | - | - |
18.80 | 0.740 | 59.06 | 2.32 | R 1/2 | 8 7/8 | - | - |
18.89 | 0.748 | 59.34 | 2.35 | R 3/4 | 9 | - | 18 |
19.10 | 0.752 | 60.00 | 2.36 | S | 9 1/8 | 60 | - |
19.22 | 0.757 | 60.38 | 2.38 | S 1/4 | 9 1/4 | - | - |
19.31 | 0.760 | 60.66 | 2.39 | S 1/2 | 9 3/8 | - | - |
19.41 | 0.764 | 60.98 | 2.40 | S 3/4 | 9 1/2 | - | 19 |
19.51 | 0.768 | 61.29 | 2.41 | T | 9 5/8 | 61 | - |
19.62 | 0.772 | 61.64 | 2.43 | T 1/4 | 9 3/4 | - | - |
19.84 | 0.781 | 62.33 | 2.45 | T 1/2 | 10 | 62 | 20 |
20.02 | 0.788 | 62.89 | 2.48 | U | 10 1/4 | - | 21 |
20.20 | 0.797 | 63.46 | 2.50 | U 1/2 | 10 1/2 | 63 | 22 |
20.32 | 0.800 | 63.84 | 2.51 | V | 10 5/8 | - | - |
20.44 | 0.805 | 64.21 | 2.53 | V 1/4 | 10 3/4 | 64 | - |
20.68 | 0.814 | 64.97 | 2.56 | V 1/2 | 11 | - | 23 |
20.76 | 0.817 | 65.22 | 2.57 | W | 11 1/8 | 65 | - |