Use the steps below to find a comfortable fit. Measure at room temperature and repeat for accuracy.
Measure a ring you own
Choose a ring that fits the intended finger. Lay it flat and measure the inside diameter straight across the centre, from inner edge to inner edge, in millimetres. Match that measurement to the table.
Measure your finger
Wrap a narrow strip of paper or a flexible measuring tape around the finger. Mark where it meets, then measure the length in millimetres. Match the circumference to the table. For the most reliable fit, confirm the size with a jeweller.
Approximate ring size conversions
| Internal diameter (mm) |
Circumference (mm) |
US/CAN |
UK/AUS |
German |
| 14.1 | 44.3 | 3 | F | 44 |
| 14.5 | 45.6 | 3.5 | G | 46 |
| 14.9 | 46.8 | 4 | H | 47 |
| 15.3 | 48.1 | 4.5 | I | 48 |
| 15.7 | 49.3 | 5 | J | 49 |
| 16.1 | 50.6 | 5.5 | K | 50 |
| 16.5 | 51.8 | 6 | L | 52 |
| 16.9 | 53.1 | 6.5 | M | 53 |
| 17.3 | 54.3 | 7 | N | 54 |
| 17.7 | 55.6 | 7.5 | O | 56 |
| 18.1 | 56.9 | 8 | P | 57 |
| 18.5 | 58.1 | 8.5 | Q | 58 |
| 19.0 | 59.7 | 9 | R | 60 |
| 19.4 | 61.0 | 9.5 | S | 61 |
| 19.8 | 62.2 | 10 | T | 62 |
| 20.2 | 63.5 | 10.5 | U | 64 |
| 20.6 | 64.7 | 11 | V | 65 |
| 21.0 | 66.0 | 11.5 | W | 66 |
| 21.4 | 67.2 | 12 | X | 68 |
Sizes are approximate and can vary between brands. If you are between sizes, have a wide band, or are unsure, we recommend having your finger professionally measured.