Just a quick post to say I've added in a Hinge distance calculator for Tilt lens users.
In the above screen grab, for my 24mm TS-E, we see the Hinge Calculator showing that a tilt of 2.5 degrees gives a hinge distance of 55cm.
Additionally DOFIS tells us that the front principal, along the tilted optical axis, from where the hinge ‘line’ is measured, parallel to the sensor plane, is at 127mm from the sensor. In the above focus was set at infinity, ie no lens extension. At minimum focus DOFIS would tell you that the front principal is positioned at about 135mm from the sensor.