Wrap a piece of thread or string around your finger, leaving a little slack. Then place it against a ruler or tape measure.
| Size | Home measurement | Ring diameter |
| 6 | 48 mm | 14.6 mm |
| 9 | 51 mm | 15.5 mm |
| 10 | 52 mm | 15.8 mm |
| 11 | 53 mm | 16.2 mm |
| 12 | 54 mm | 16.5 mm |
| 13 | 55-56 mm | 16.8 mm |
| 14 | 57-58 mm | 17.2 mm |
| 15 | 59 mm | 17.5 mm |
| 17 | 62 mm | 17.8 mm |
| 19 | 64 mm | 18.7 mm |