I just posted a revised version of my home theater calculator.  The new revision adds the following enhancements:

• Added feature to allow calculation of Visual Acuity Viewing Distance based on eyesight of the viewer. (The default is 20/20 vision; changing the input to 20/10 vision with show that the viewer will be able to spot resolution deficiencies at much greater distances due to more acute eyesight.)
• Fixed bug in the aspect ratio input that caused international users to have problems (problem was related to using “,” as decimal delimiter instead of “.”)
• Added cells to the far right of the spreadsheet to allow changing and adding custom screen aspect ratios.As

As before, the spreadsheet still has the following features:

• recommended viewing distances for a given screen size – for both flat panels and projectors (based on THX and SMPTE standards)
• recommended viewing distances for a given display resolution – 480p, 720p, 1080p/1080i, 1440p, etc (based on Visual Acuity standards)
• various screen aspect ratios (4:3, 16:9, 1.85:1, 2.35:1, custom ratios, etc.)
• projector screen size & screen brightness with guidelines for recommended values (based on projector brightness and screen gain)
• projector screen size & projector mounting location (based on min/max projector throw distances)
• seat locations, a second row stadium seating platform height calculation, and a few other goodies.

Here is the link:

https://carltonbale.com/home-theater/home-theater-calculator/