if you are a loose fitting 13 you could possibly fit into a 12 soap shoe. if you can fit into a normal size 12 shoe chances are you can wear a 12 in soap shoes. i normally wear a 10 but can fit into size 9 soaps. one thing u could try is taking the sole out of a size 12 shoe and see if it gives u more room... i can fit into an 8 by doing that....you could always put a thinner sole in the shoe... you can also keep a check on ebay...they have some 14s on there that are mb tanks but the only others are 12s.