In order to help users in understanding Ring sizes and parameters used in different countries, we have pulled out this chart to assist you in doing so. The chart includes inner diameter as well as circumference of a ring in inches and millimetres.
The Ring sizes are measured using simple tools such as Ring sizer stick (or Ring Mandrel) and Ring finger sizer as shown in the images below.
The size parameters differ country wise as shown in the table below.
Conversion chart for ring sizes | ||||||||
Inside diameter | Inside circumference | Sizes | ||||||
(in) | (mm) | (in) | (mm) | US, | UK, | China, | India | Italy, |
0.458 | 11.63 | 1.44 | 36.5 | 0 |
|
|
|
|
0.466 | 11.84 | 1.46 | 37.2 | ¼ |
|
|
|
|
0.474 | 12.04 | 1.49 | 37.8 | ½ | A |
|
|
|
0.482 | 12.24 | 1.51 | 38.5 | ¾ | A½ |
|
|
|
0.49 | 12.45 | 1.54 | 39.1 | 1 | B | 1 |
|
|
0.498 | 12.65 | 1.56 | 39.7 | 1¼ | B½ |
|
|
|
0.506 | 12.85 | 1.59 | 40.4 | 1½ | C |
|
| 0.5 |
0.514 | 13.06 | 1.61 | 41 | 1¾ | C½ |
| 1 | 1 |
0.522 | 13.26 | 1.64 | 41.7 | 2 | D | 2 | 2 | 1.75 |
0.53 | 13.46 | 1.67 | 42.3 | 2¼ | D½ |
|
| 2.25 |
0.538 | 13.67 | 1.69 | 42.9 | 2½ | E | 3 | 3 | 3 |
0.546 | 13.87 | 1.72 | 43.6 | 2¾ | E½ |
| 4 | 3.5 |
0.554 | 14.07 | 1.74 | 44.2 | 3 | F | 4 |
| 4.25 |
0.562 | 14.27 | 1.77 | 44.8 | 3¼ | F½ | 5 | 5 | 4.75 |
0.57 | 14.48 | 1.79 | 45.5 | 3½ | G |
|
| 5.5 |
0.578 | 14.68 | 1.82 | 46.1 | 3¾ | G½ | 6 | 6 | 6 |
0.586 | 14.88 | 1.84 | 46.8 | 4 | H | 7 |
| 6.75 |
0.594 | 15.09 | 1.87 | 47.4 | 4¼ | H½ |
| 7 | 7.5 |
0.602 | 15.29 | 1.89 | 48 | 4½ | I | 8 | 8 | 8 |
0.61 | 15.49 | 1.92 | 48.7 | 4¾ | J |
| 9 | 8.75 |
0.618 | 15.7 | 1.94 | 49.3 | 5 | J½ | 9 |
| 9.25 |
0.626 | 15.9 | 1.97 | 50 | 5¼ | K |
| 10 | 10 |
0.634 | 16.1 | 1.99 | 50.6 | 5½ | K½ | 10 |
| 10.5 |
0.642 | 16.31 | 2.02 | 51.2 | 5¾ | L |
| 11 | 11.25 |
0.65 | 16.51 | 2.04 | 51.9 | 6 | L½ | 11 | 12 | 11.75 |
0.658 | 16.71 | 2.07 | 52.5 | 6¼ | M | 12 |
| 12.5 |
0.666 | 16.92 | 2.09 | 53.1 | 6½ | M½ | 13 | 13 | 13.25 |
0.674 | 17.12 | 2.12 | 53.8 | 6¾ | N |
|
| 13.75 |
0.682 | 17.32 | 2.14 | 54.4 | 7 | N½ | 14 | 14 | 14.5 |
0.69 | 17.53 | 2.17 | 55.1 | 7¼ | O |
| 15 | 15 |
0.698 | 17.73 | 2.19 | 55.7 | 7½ | O½ | 15 |
| 15.75 |
0.706 | 17.93 | 2.22 | 56.3 | 7¾ | P |
| 16 | 16.25 |
0.714 | 18.14 | 2.24 | 57 | 8 | P½ | 16 | 17 | 17 |
0.722 | 18.34 | 2.27 | 57.6 | 8¼ | Q |
|
| 17.5 |
0.73 | 18.54 | 2.29 | 58.3 | 8½ | Q½ | 17 | 18 | 18.25 |
0.738 | 18.75 | 2.32 | 58.9 | 8¾ | R |
| 19 | 19 |
0.746 | 18.95 | 2.34 | 59.5 | 9 | R½ | 18 |
| 19.5 |
0.754 | 19.15 | 2.37 | 60.2 | 9¼ | S |
| 20 | 20.25 |
0.762 | 19.35 | 2.39 | 60.8 | 9½ | S½ | 19 | 21 | 20.75 |
0.77 | 19.56 | 2.42 | 61.4 | 9¾ | T |
|
| 21.5 |
0.778 | 19.76 | 2.44 | 62.1 | 10 | T½ | 20 | 22 | 22 |
0.786 | 19.96 | 2.47 | 62.7 | 10¼ | U | 21 | 23 | 22.75 |
0.794 | 20.17 | 2.49 | 63.4 | 10½ | U½ | 22 |
| 23.25 |
0.802 | 20.37 | 2.52 | 64 | 10¾ | V |
| 24 | 24 |
0.81 | 20.57 | 2.54 | 64.6 | 11 | V½ | 23 | 25 | 24.75 |
0.818 | 20.78 | 2.57 | 65.3 | 11¼ | W |
|
| 25.25 |
0.826 | 20.98 | 2.59 | 65.9 | 11½ | W½ | 24 | 26 | 26 |
0.834 | 21.18 | 2.62 | 66.6 | 11¾ | X |
|
| 26.5 |
0.842 | 21.39 | 2.65 | 67.2 | 12 | X½ | 25 | 27 | 27.25 |
0.85 | 21.59 | 2.67 | 67.8 | 12¼ | Y |
| 28 | 27.75 |
0.858 | 21.79 | 2.7 | 68.5 | 12½ | Z | 26 |
| 28.5 |
0.866 | 22 | 2.72 | 69.1 | 12¾ | Z½ |
| 29 | 29 |
0.874 | 22.2 | 2.75 | 69.7 | 13 |
| 27 | 30 | 29.75 |
0.882 | 22.4 | 2.77 | 70.4 | 13¼ | Z1 |
|
| 30.5 |
0.89 | 22.61 | 2.8 | 71 | 13½ |
|
| 31 | 31 |
0.898 | 22.81 | 2.82 | 71.7 | 13¾ | Z2 |
| 32 | 31.75 |
0.906 | 23.01 | 2.85 | 72.3 | 14 | Z3 |
|
| 32.25 |
0.914 | 23.22 | 2.87 | 72.9 | 14¼ |
|
| 33 | 33 |
0.922 | 23.42 | 2.9 | 73.6 | 14½ | Z4 |
|
| 33.5 |
0.93 | 23.62 | 2.92 | 74.2 | 14¾ |
|
| 34 | 34.25 |
0.938 | 23.83 | 2.95 | 74.8 | 15 |
|
| 35 | 34.75 |
0.946 | 24.03 | 2.97 | 75.5 | 15¼ |
|
|
| 35.5 |
0.954 | 24.23 | 3 | 76.1 | 15½ |
|
| 36 | 36.25 |
0.962 | 24.43 | 3.02 | 76.8 | 15¾ |
|
|
| 36.75 |
0.97 | 24.64 | 3.05 | 77.4 | 16 |
|
| 37 | 37.5 |
Ring sizes can be measured physically by a plastic or metal ring sizer, or by measuring the girth of a ring that already fits. There are also online measuring tools available, though they may not be as precise as checking for the size physically.
The circumference of the ring (inner circle) is the distance around it. It is calculated based on the formula, π × diameter (where π=3.14). For example, the Indian size 10 has a diameter 15.9 mm. Hence the circumference would be 3.14 x 15.9 = Approx. 50 mm.
The average ring size for women in India is around Size 13-14 and for men, it is between Size 16-18.
Love creating designs and coming up with stunning visuals on the computer? Aspiring to become a Jewerly Designer and showcase your work to the world? Learn the creative and technical skills needed to begin career as a jewelery designer with CAD Jewelry Designing courses for upcoming year at JK Diamonds.
