It's a 140" wide 2.40 aspect screen. It's 58.3" tall and the diagonal is 151.6".
When projecting a 16:9 image, the width will be 103.8" with a diagonal measurement of around 120", if my math is correct.
I'll find out soon if my JVC X70 is up to the task of lighting this up. The room is completely light controlled, when I turn off the lights I can't see my hand in front of my face.
Early on in this build, I projected an image on a wall to determine the size of screen to get. The image looked plenty bright on a tan wall, and this was before the room was completely light proofed. When doing this, we projected Avatar in 16:9, the image was about 110" diagonal, and wife said "this hardly looks bigger than our TV", which is a 73" diagonal Mits.
I zoomed the image and she kept saying to go bigger, go bigger.. I finally decided this was the biggest I could go. Did I mention we like a big image?
Our first row seating is going to be 10.5 ft (or 0.9 screen widths). This might be a bit overwhelming for a 2.39 movie, but should be great for 16:9 movies. The second row wil be at 16 ft (or 1.37 screen widths). This should be great for 2.39 movies, but a little less impressive for 16:9 movies. I may end up choosing front or back row depending upon the content and size of the movie.
The sound system is going to be optimized for the front row, so I'm planning on spending most of my time there.