@ok same size I’d say. I feel like Jordan 1’s run slightly big, and 12.5 isn’t often made,.. so tough to say. 12’s in dunks are pretty snug for me, but other Nike’s like the Sb blazer low GT are okay (run long). Usually 12s are snug and 13s a bit of toe room.
I grabbed a size 12 and 13 dunk and can take a pic to compare just trying finish this lasagne haha