Below you can see the front view size comparison of Canon G9 X and Canon G16. Canon G9 X is clearly the smaller of the two cameras. Its body is 11mm narrower, 18mm shorter and 9mm thinner than Canon G16.
Canon G9 X vs Canon G16 - Front View
Canon G9 X vs Canon G16 - 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