It's not that difficult to find out what size a ring needs to be in order to fit properly. You can measure the ring size with a thin strip of paper or a non-elastic thread.

 

Wrap the strip of paper or thread around the corresponding finger, exactly between the knuckle and the finger joint. Mark the point where the paper or thread meets and measure the length of the piece up to the mark using a ruler.

It is important to remember that this measures the circumference of the ring, not the diameter, because in the shop the ring size is often given with the diameter.

The circumference of ring sizes 4 to 13 corresponds to the following measurements:

 

Ring size 4: 4.57cm

Ring size 5: 4.82cm

Ring size 6: 5.06cm

Ring size 7: 5.31cm

Ring size 8: 5.57cm

Ring size 9: 5.81cm

Ring size 10: 6,06cm

Ring size 11: 6.30cm

Ring size 12: 6.55cm

Ring size 13: 6.80cm