Below you can see the front view size comparison of Sigma Quattro H and Canon 6D MII. Canon 6D MII is 3mm narrower and 16mm thinner than Sigma Quattro H but it is also 16mm taller.
Sigma Quattro H vs Canon 6D MII - Front View
Sigma Quattro H vs Canon 6D MII - 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