Isabel Marant Reversible Floral Patterned Bucket Hat

This is such a cool hat! Was given to me as a gift and unfortunately its a little too small for me. I don't see or remember a size tag on it, but I would say I have a pretty average size head, so this must be a small? Anyway this pattern is rare and totally sold out so I thought I should posh it! I maybe wore it outside the house one time, it's basically brand new.