Thank you AMJ! My DH originally gave me the size 20 and it fit but I wanted it to be a little looser since I would be wearing it all of the time so we got the next size up... I'm a size 7in wrist so I can wear the 19,20,or 21 if I wanted to but 19 and 20 were not perfect for me... and in the end you have to make sure that you are 100% comfortable with it because its meant to be worn 24/7, good luck!