Chart for screen size vs viewing distance?

[Uniquely]

I've seen the charts that show at what seating distance differences in resolution become noticable for different screen sizes. Has anyone ever seen a chart that shows the largest screen size that one can wholy view (i.e. see entire screen in field of vison without having to turn eye/head) from various seating distances?

I became curious about this after seeing an article about a new 85" plasma that said you would need a 74" wide stand to place it on. My new entertainment unit is 72" and I can not see the whole thing from my seating position without turning. Something like that could be helpful in deciding what size tv to buy or if front projection would be enjoyable in your set up.