We have 4 family members who regularly wear Sambas.  This time around a worn out 10.5 needed to be replaced with a same size.  The 10.5 we received was just a bit smaller than the old pair.  Amazon was great and let us exchange it for the 11.  When we held the 11 up against the old 10.5 it was maybe a fraction less in length - basically the same.  Just FYI if you are torn between sizes, I would get the half size up.