How far should you sit from a 42-inch TV used as a monitor? Ergonomic guide

How this is calculated

Typical desktop monitors are viewed from a distance of about 2.5 feet (75 centimeters) away. If you put a massive 42 inch screen at that exact same distance, it will cover well over 60 degrees of your human vision. This forces you to crane your neck constantly to see the corners of the user interface. To get the screen down to a comfortable 30 degree to 40 degree field of view that matches standard ergonomics, you must sit between 4.2 feet (1.3 meters) and 5.7 feet (1.7 meters) away from the panel.

Verdict

The trap is that standard desk distance puts a 42-inch panel at over 60 degrees of horizontal field of view, which forces you to physically turn your head to read UI elements at the corners and produces the neck strain and eye fatigue the spec is meant to prevent. The fix lands in the field-of-view math: 4.2 feet (1.3 m) anchors to THX's 40-degree immersive standard and 5.7 feet (1.7 m) anchors to SMPTE's 30-degree ergonomic standard, with desktop work landing in either band depending on tolerance for peripheral wrap. The honest consequence is that a standard 24-inch-deep office desk can't deliver any of those distances, which is why the practical deployment is wall-mounted behind the desk, a custom 30-36 inch deep tabletop, or a floor stand behind the desk. The 42-inch LG C4 OLED at ~105 PPI is the popular pick because it's the only way to get OLED contrast at that field of view without buying a curved 49-inch super ultrawide.