Below you can see the front view size comparison of Sony A6000 and Canon M3. Canon M3 is 9mm narrower and 1mm thinner than Sony A6000 but it is also 1mm taller.
Sony A6000 vs Canon M3 - Front View
Sony A6000 vs Canon M3 - 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