Guideline height for mounting

[mit rraf]

hello.
I am planning to mount a 46-50" screen in a currently empty living room and wondered if there was a suggested height for this? In an ideal world i would get the occupants to sit on their furniture and mark the line of sight and fit accordingly, but there is no furniture and the wall is yet to be made!
I was proposing to use a flat bracket like the one below as the new wall will be plumb:

VonHaus 33-60" Tilt TV Wall Mount Bracket with Built-In: Amazon.co.uk: Electronics

Thanks

 

[Roohster]

Ideally the centre of the screen should be at eye level when sitting down.