Calculate Platform / Riser height

Riser Height?

How high does a platform have to be, so that the back row has an optimal view of the screen?

The optimum height ...

... of a riser in a home theater can be calculated with few measurements. It includes the distance and seat height of the first row of seats, the height of the bottom edge of the screen, and the seat row spacing.

Important:
Make sure there is sufficient room height between the platform and the ceiling so that it is still possible to stand upright.