What's the 30-degree rule for TVs?

The Society of Motion Picture and Television Engineers recommends a minimum 30-degree field of view, about 1.6 times the screen diagonal. A 55-inch TV should sit 7 ft 4 in away, a 75-inch TV 10 ft, and an 85-inch TV 11 ft 4 in. A 40-degree view, 1.2 times the diagonal, places a 65-inch TV 6 ft 5 in from the viewer. A 62-degree view puts the same screen 4 ft 6 in distant. These distances reduce eye strain and enhance immersion, though actual seating may vary with room layout and personal preference.