Ring Size Conversion Chart
| CIRCUMFERENCE ( in mm ) |
U.K. | U.S. | DIAMETER ( in mm ) |
JAPANESE |
|---|---|---|---|---|
| 46.5mm | H 1/2 | 4 1/2 | 14.8mm | 7 |
| 48mm | I 1/2 | 5 | 15.2mm | 8 |
| 49mm | J 1/2 | 5 1/2 | 15.6mm | 9 |
| 50.5mm | L | 6 | 16mm | 10 |
| 52mm | M | 6 1/2 | 16.4mm | 12 |
| 53mm | N | 7 | 16.8mm | 13 |
| 54.5mm | O | 7 1/2 | 17.3mm | 14 |
| 55.5mm | P | 8 | 17.7mm | 15 |
| 57mm | Q | 8 1/2 | 18.1mm | 16 |
| 58mm | Q 1/2 | 9 | 18.5mm | 17 |
| 59.5mm | R 1/2 | 9 1/2 | 18.9mm | 18 |
| 61mm | S 1/2 | 10 | 19.3mm | 20 |
| 62mm | T 1/2 | 10 1/2 | 19.7mm | 21 |
| 63.5mm | U 1/2 | 11 | 20.1mm | 22 |
| 64.5mm | V 1/2 | 11 1/2 | 20.6mm | 24 |
| 66mm | W 1/2 | 12 | 21mm | 25 |
| 67.5mm | Y | 12 1/2 | 21.4mm | 26 |
| 68.5mm | Z | 13 | 21.8mm | 27 |
| 70mm | Z+1 | 13 1/2 | 22.2mm | 28 |
| 71mm | Z+2 | 14 | 22.6mm | 29 |
| 72.5mm | Z+3 | 14 1/2 | 23mm | 31 |
| 74mm | Z+4 | 15 | 23.4mm | 32 |
How To Measure Your Finger for a Ring Size
This can be done very simply. Take a piece of string or a thin strip of paper. Wrap it around the base of the appropriate ring finger. Use a pen to mark the point where it overlaps, forming a complete circle. Measure the length from the starting end of the string/paper to the pen mark, in millimeters. You will then have the circumference measurement of your finger in millimeters, and can then use the ring size conversion chart given on this site to work out your ring size according to several different systems.
It is a good idea to measure the finger at the end of the day, when the finger is at its largest, and not to do it when the finger is cold, as this will make it unusually small. Bear in mind that finger sizes change throughout the day.
If you are buying a ring as a surprise, you could obviously ask a friend of your partners for her ring size. Failing this, however, you could take a ring to a jewellers for sizing. If it is not possible to do this without her noticing, the ring can be slid down a tapered candle or down your finger, then the circumference of the candle or the point of your finger measured as suggested above. Alternatively, the ring can be pressed into a piece of soap, clay or other malleable substance. If you do not have this to hand, you could use a pen to mark the inside of the ring on a piece of paper and take this to a jewellers to find out its size.
