Below you can see the front view size comparison of Canon R and Nikon Z6. Nikon Z6 is 2mm narrower and 16mm thinner than Canon R but it is also 3mm taller.
Canon R vs Nikon Z6 - Front View
Canon R vs Nikon Z6 - 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