Hi Hutch306,

It is very easy to find the pitch.
Imagine you have a roof covering a extension of 120", and the difference between the lowest point and the top of the roof is 30", so your pitch will be

X/12= 30"/ 120" => X= (30 x 12) / 120 => X= 3

So your pitch will be 3:12. You can check this in the image attached

This is the only way I know to set both ends at the right elevation

Hope this helps

Patricia