Black GUCCI 'SL73' Sneakers Sz 8.5/9

The inside shows the size to be 8.5. However, I’m not clear whether this is UK size, which would be a U.S. 9. In measuring the shoe from the outside, toe to heel, it measure 11.5 inches. The insole measure 11&1/16 inches from heel to toe. Worn indoors only 1-2 times.