Below you can see the front view size comparison of Nikon D5 and Sony A7R II. Sony A7R II is clearly the smaller of the two cameras. Its body is 33mm narrower, 63mm shorter and 32mm thinner than Nikon D5.
Nikon D5 vs Sony A7R II - Front View
Nikon D5 vs Sony A7R II - 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