How far should you sit from a 48-inch TV used as a monitor? Setup guide

How this is calculated

To keep a 48 inch display within the ergonomic 40 degree field of view, your eyes need to be roughly 4.8 feet (1.5 meters) away from the glass. At standard office desk distances, the edges of the screen will literally be out of focus due to the viewing angles, and it will require intense physical head movement just to read application menus or check minimaps in video games.

Verdict

The 4.8-foot figure anchors to THX's 40-degree immersive target and the 6.5-foot end to the historical SMPTE EG 18-1994 30-degree reference, with the 48-inch panel area being equivalent to four stitched 24-inch 1080p monitors. The same desk-depth math that applies to the 42-inch case applies harder here: at standard 24-inch desk depth the panel covers a very wide field of view, and reading menus or game minimaps can require extra eye or head movement. SMPTE withdrew EG 18 in 2003, so the 30-degree value is a geometry reference, not a current ergonomic standard. The deployment pattern that works is wall mounting behind the desk or a custom deep tabletop, not a floor stand on a shallow desk, because the 4.8-foot minimum is a hard constraint that a 24-inch-deep desk physically can't deliver.