Below you can see the front view size comparison of Nikon D7200 and Sony A7. Sony A7 is clearly the smaller of the two cameras. Its body is 9mm narrower, 13mm shorter and 28mm thinner than Nikon D7200.
Nikon D7200 vs Sony A7 - Front View
Nikon D7200 vs Sony A7 - Top View
The chart below depicts how two cameras compare with average dimensions of the cameras in their class.
Camera Size Comparison
Select Two Cameras for Size Comparison