Monitor Viewing Distance Calculator

The optimal viewing distance depends on screen size, resolution, and what you are doing. Sitting too close causes eye strain. Sitting too far makes small text and details hard to see.

THX recommended viewing angle: 40 degrees for an immersive cinema experience. SMPTE (Society of Motion Picture and Television Engineers): 30 degrees for comfortable, extended viewing. General computing: 20 degrees field of view is comfortable for productivity.

Distance formula based on viewing angle: Distance = (Screen Width / 2) / tan(Angle / 2)

Height is what actually drives the answer, not the diagonal

A 34-inch ultrawide and a 27-inch 16:9 have almost exactly the same height, and they get sat at almost exactly the same distance. That is not a coincidence. The extra width on an ultrawide is meant to spill into your peripheral vision, so pushing the screen back until the whole width fits a cinema viewing angle defeats the point of buying one.

So this calculator works out the screen height from the diagonal and the aspect ratio, then applies the target angle to the equivalent 16:9 width for that height. For a 16:9 screen it is the plain formula above. For a 21:9 or 32:9 panel it gives the distance a screen of that height wants, and lets the extra width do its job.

Resolution matters, but usually less than you would think At higher resolutions you can sit closer without seeing individual pixels.

• 1080p (Full HD): pixels start showing closer than about 1.5× screen height
• 1440p (QHD): about 1.2× screen height
• 4K (UHD): about 0.75× screen height

Here is the part most guides leave out: on a desk monitor that limit almost never binds. The comfortable viewing angle already puts you at roughly 2.3 to 3.2 times the screen height, well beyond even the 1080p limit. Resolution decides how sharp text looks, not how far back you sit. The calculator reports both numbers so you can see which one is doing the work.

General guidelines by screen size (immersive gaming, the numbers this calculator returns):

Usage adjustments:

• Competitive gaming (42°): closest of the four. Small monitor, pulled in, so targets at the screen edge stay inside your vision without a head turn.
• Gaming, immersive (36°): the cinema-style compromise, near the THX figure.
• Productivity (32°): a little further back. You are reading text for hours, not reacting, and the extra distance is easier on the eyes.
• Video watching (31°): furthest back, close to the SMPTE 30° recommendation for long comfortable viewing.

Ergonomic tips:

• The top of the screen should be at or slightly below eye level.
• The screen should be tilted back 10-20 degrees.
• The center of the screen should be about 15-20 degrees below your horizontal eye line.
• Follow the 20-20-20 rule: Every 20 minutes, look at something 20 feet away for 20 seconds.