How far should you sit from a 120-inch projector screen? Seat and room guide

How this is calculated

The 40 degree seat is 12.0 feet (3.6 meters), and the 30 degree seat from the historical SMPTE EG 18-1994 reference is 16.3 feet (5.0 meters). SMPTE withdrew EG 18 in 2003, so use the 30 degree number as a geometry reference, not a current recommendation. The screen is 8.7 feet (2.7 meters) wide, and that's the number to check against your wall. These numbers assume a 16:9 screen. A 2.35:1 or 16:10 screen of the same diagonal has a different width, so the band moves.

Verdict

Inside the band, the screen fills a view from 40 to 30 degrees. At 12.0 feet (3.6 m) or closer, the picture reaches past the 40 degree target, and your eyes have to cover more of it. Farther back than 16.3 feet (5.0 m), it covers less than a 30 degree view and loses some of its impact. A bigger picture spreads the projector's light over more area, so room light cuts into contrast more at this size.