I'm a size 12 but have freakishly large wrists. My DH bought me the usual size, 19" possibly? It didn't fit so I went in and explained and they swapped it no probs for the larger/est. 24" possibly? May be worth looking on the website, but the 24/26 is generous on me, and I normally have to wear bespoke bracelets! HTH...
I nearly went in to the store today but thought they might laugh at me in my sick covered attire (thanks DD2) and fat wrists so I chickened out. Should say that I can't find my tape measure for love nor money. Typical.
I'm bigger and Pandora fits me fine infact my first was too big. They do the bracelets upto 23cm.
You should go into the shop and try them out because the size you need depends on how you intend to have your bracelet - if you're going to fill up your bracelet you have to size up a little bit as the charms and beads detract from some of the length.