I have always loved Birkenstock's, and I have a wide foot, and the Medium works just fine for me, even with this style!  They are SO comfortable, that I even forget that I have them on!  Fast Shipment, Excellent Craftsmanship as ALWAYS!  I would NEVER expect anything less from this company!  PLUS, after having 10 back surgeries, these are the ONLY shoes that I can wear, without my feet cramping from the Nephropathy!  17 years of wearing these, and I've yet to be disappointed!