This is the method I use to spec out meeting rooms at work but all the info is online. This one is a good resource: https://www.rtings.com/tv/reviews/by-size/size-to-distance-relationship
Screen Size
Recommended Mixed Usage Distance
(30°)
Recommended Cinema Distance
(40°)
25"
3.4' (1.04 m)
2.5' (0.77 m)
30"
4.1' (1.24 m)
3' (0.92 m)
35"
4.8' (1.45 m)
3.5' (1.07 m)
40"
5.5' (1.66 m)
4' (1.22 m)
45"
6.1' (1.86 m)
4.5' (1.37 m)
50"
6.8' (2.06 m)
5' (1.53 m)
55"
7.5'...