Below you can see the front view size comparison of Canon M6 and Sigma Quattro. Canon M6 is clearly the smaller of the two cameras. Its body is 35mm narrower, 27mm shorter and 46mm thinner than Sigma Quattro.
Canon M6 vs Sigma Quattro - Front View
Canon M6 vs Sigma Quattro - 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