Since the buck has only one ear out, I can only use boneaddict's math to find the width of one side of the antlers. Using his math I get 106.25 units from the center of the head to the outside of the ear. Similarly, I get 156.25 units from the center of the head to the outside of the furthest antler.
Therefore:
11 inches= 106.25X
X = .103529411........
156.25X = 16.18 inches
Assuming the buck is symmetrical and that I correctly judged the center of the head we have a 32"+ buck! That's a big buck!