The standard size fits most. This style does not need to be exact as they are adjustable, but large enough to fit over the hand. Measure around the widest part of your hand (typically across the knuckles). Corded bracelets are adjustable with an opening of 8.5" standard. They close up to about 5.25" Corded bracelets are not returnable if they are not the standard 8.5" Please make sure to measure carefully as too small will not fit.
Measure around your wrist and add to the measurement for how tight/loose you would like the bracelet on your wrist (typically .25" - .50" larger than your actual wrist measurement).