Screen Size Approximation Chart
I am surprised that people still misjudge the size of the screen needed. It is easy to test out and make minor adjustments but that might not be enough.
This is a guide from Microsoft that might help you.
Use it when someone asks you how large of a screen you need.
|Audience size||Suggested screen size|
|3-5 people||21 inches diagonal (53.34 cm)|
|5-9 people||29 inches diagonal (73.66 cm)|
|10-15 people||37 inches diagonal (93.98 cm)|
|16-35 people||60 inches diagonal (152.4 cm)|
|36-50 people||72 inches diagonal (182.88 cm)|
|51-140 people||120 inches diagonal (304.8 cm)|
|141-220 people||150 inches diagonal (381.0 cm)|
|221-390 people||200 inches diagonal (508.0 cm)|
|391+ people||300 inches diagonal (762.0 cm)|
Remember, the average person doesn’t have perfect vision.
Err on the side of caution and make the screen a bit bigger.