How far should you sit from a 75-inch TV? Cinematic seating math

How this is calculated

For a cinematic 40 degree field of view that rivals a commercial theater, the math places your ideal seating position at 7.5 feet (2.3 meters) away. However, many users actually find this distance overwhelmingly large for daily casual use. The SMPTE recommendation of a 30 degree viewing angle pushes the required viewing distance back to a much more manageable 10.2 feet (3.1 meters). This 10 foot distance is generally much easier to achieve in a modern open floor plan home.

Verdict

The THX 40-degree standard puts your couch at 7.5 feet (2.3 m) for full cinema immersion and the SMPTE 30-degree standard puts it at 10.2 feet (3.1 m) for relaxed mixed viewing, with the 10-foot SMPTE end being the practical default for an open-floor-plan living room because it accommodates the wider seating and group viewing that real rooms demand. Below 7.5 feet the 75-inch panel covers too much horizontal field of view for daily content and forces head-sweeping to track action, which is the actual cause of the neck pain the spec avoids. Above 10 feet the perceived detail of 4K's 59 PPI starts to soften toward what a 65-inch would deliver at 8.8 feet, so the verdict anchors to that 7.5-10 foot band: above 11 feet you'd see more detail on an 85-inch at the same distance.