I'll start off by saying that I'm a pretty big Excel nerd. I've been keeping a spreadsheet of all of my movies (including year released, running time, rating, aspect ratio, etc.) for years. When I started looking into building my own theater I looked at my spreadsheet to see how many movies I had of each aspect ratio to help in figuring out the kind of screen to go with. Then I wanted to know possible screen sizes based on aspect ratio and width. After thinking I was figuring out what I wanted for a screen I started reading up on viewing distances based on screen size. I'm sure you guys know how this madness goes.
Well, I'm constantly re-thinking what I want to do with my theater, which means constantly re-thinking the screen and seating. It only made sense to me to build a spreadsheet that could answer all the various questions for me.
What's the diagonal length on a 100" wide 2.35 screen?
If I go with a 96" wide 16x9 screen how tall will my 2.40:1 image be?
What's the viewing angle if I'm sitting 144" back from a 120" wide screen?
I got the idea for the viewing distance stuff from C.M. Collins' page
Anyway, I built it, and it works.
There are pre-built options for most common aspect ratios.
For less common aspect ratios there's an area to enter what you want (2.55:1, 21x9, etc.)
And the second tab has all the stuff pertaining to screen width, viewing angle, and seating distance.
I'm sure this stuff could easily be put together on a webpage, but this worked for me. Hopefully it'll work for some of you, too. There's pretty detailed instructions in the spreadsheet. Let me know what you think.
Screen Size, Aspect Ratio, Distance, Angle Calculator.xlsx 31k .xlsx file