Take buckle apart and and pull the free ends of the cord thru the other part of the buckle, sliding it up towards the attached part. You're going to measure the distance between the two buckle ends for the bracelet size for your wrist. Add about 1 inch to your measured wrist length, this will make the finished bracelet a comfortable fit. You're measuring from the end of the female part of the buckle to the flat part of the male end of the buckle(the part with the prongs, they don't count for the measurement because the fit inside the female part of the buckle when the bracelet is closed.).