Find your ring size
Our ring size is the inner diameter of the ring in millimetres.
1With a ring that fits
Place a well-fitting ring on a ruler and measure the inside in mm. 18 mm = ring size 18.
2With a piece of string or paper
Wrap it around the base of your finger, mark where it meets and measure the length. Find that length under Circumference.
| Ring size | Diameter | Circumference | US | UK |
|---|---|---|---|---|
| 14 | 14 mm0.55 in | 44 mm1.73 in | 3 | F |
| 15 | 15 mm0.59 in | 47.1 mm1.85 in | 4 | H½ |
| 16 | 16 mm0.63 in | 50.3 mm1.98 in | 5½ | K |
| 17 | 17 mm0.67 in | 53.4 mm2.10 in | 6½ | M |
| 18 | 18 mm0.71 in | 56.5 mm2.22 in | 8 | O½ |
| 19 | 19 mm0.75 in | 59.7 mm2.35 in | 9 | R |
| 20 | 20 mm0.79 in | 62.8 mm2.47 in | 10½ | T½ |
| 21 | 21 mm0.83 in | 66 mm2.60 in | 11½ | W |
| 22 | 22 mm0.87 in | 69.1 mm2.72 in | 13 | Y½ |
Tip: between two sizes? Choose the larger one. Measure at the end of the day if you can.
US and UK sizes are rounded.