Below you can see the front view size comparison of Pentax K-1 II and Sony A7 III. Sony A7 III is clearly the smaller of the two cameras. Its body is 10mm narrower, 14mm shorter and 12mm thinner than Pentax K-1 II.
Pentax K-1 II vs Sony A7 III - Front View
Pentax K-1 II vs Sony A7 III - 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