Below you can see the front-view size comparison of the Fujifilm X-T1 and Fujifilm X-H1. The Fujifilm X-T1 is clearly the smaller of the two cameras. Its body is 11mm narrower, 7 mm shorter and 39 mm thinner than the Fujifilm X-H1.
The chart below depicts how two cameras compare with average dimensions of the cameras in their class.