Your fingers change size depending on temperature ( in warm weather fingers swell, they reduce at lower temperatures), the time of day or month. Try to find an average, considering the facts that steel rings can not be sized and the average ring size worn in the UK is a size too large.

To make the sizing easier, we have drawn up a ring size table showing all realistic sizes whether you are British, European or American. 

The size of a ring is its diameter in millimeters - expressed through letters (UK) or numbers.  If you want to be as sure as the Germans (and that is where they are made), measure the diameter of a good fit ring in millimeters (SEE PHOTO BELOW). 

Don't forget - it will not be a 100% match, you can take or (should) give a few millimeters.

After all that, if you find that you have ordered the wrong size, simply send it back .
(SEE RETURNS & GUARANTEE)

RING SIZE TABLE

diameter in mm               UK                  Europe              USA

15.05                                    I                      48                       4.5

15.40                                    J                     49                       5

15.75                                    K                     50                       5.25

16.10                                    L                      51.5                   5.50

16.50                                    M                    53                      6

16.90                                    N                    54                       6.50

17.35                                    O                    55                       7.00

17.75                                    P                     56.5                    7.50

18.20                                    Q                    58                       8

18.50                                    R                     59                       8.5

18.90                                    S                     60                        9

19.50                                    T                     61                        10   

20.00                                    U                    63                        10.50

20.30                                    V                    64                        11  

21.10                                    W                   65                        11.50 

21.20                                    X                     66                        11.75 

21.50                                    Y                     67                        12     

21.90                                    Z                      68.5                    12.50