Below you can see the front view size comparison of Canon 750D and Canon T7i. Canon T7i is clearly the smaller of the two cameras. Its body is 1mm narrower, 1mm shorter and 2mm thinner than Canon 750D.
Canon 750D vs Canon T7i - Front View
Canon 750D vs Canon T7i - 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