The size is Euro 90 or US 36. HOWEVER this can adjust down to a 27" waist if you clip on the first loop instead of the last (see photo 2) and the adjustable buckled leather piece can actually extend out by an inch (or more if you have more holes punched) or made smaller by 3 inches. It really is perfect for a tiny waist to a large one due to the versatile design. There actually is an extra hole right by the circular links too. You really can play with this piece and actually, you could wear it as a long necklace if you wanted to.