How far should a monitor be from your eyes?

“About an arm’s length.” If you have ever asked how far a monitor should sit from your face, that is the answer you got, and it is not a bad one. It is just not a measuredone, and the interesting thing about checking it against the published guidance is that the folklore turns out to be a rough stand-in for a range far wider than the phrase suggests — wide enough that “arm’s length” is less a rule than a reassurance that you are probably inside the band.

So this page does the boring, useful thing. Every distance number below is quoted from a source we read at the source: OSHA’s Computer Workstations eTool, which speaks the language of workstations, and the American Optometric Association, which speaks the language of eyes. Where they give a figure, we give theirs. Where they only give a range, we resist the urge to sharpen it into a point, because a made-up point is exactly the thing this site exists not to do.

One boundary first. This is a page about geometry— distances, screen sizes, desk depths. Stephen V. reads spec sheets; he is not an optometrist. The AOA guidance below is reported as the AOA’s, never rebuilt into a promise about your eyes. If you are getting headaches or your vision is blurring, that is a question for a clinician, and it is a good one to ask.

The arm’s-length starting point

The reason “arm’s length” endures is that it is a body-scaled measurement in a situation where the honest answer is body-scaled. A taller person with longer arms sits a little further back; a smaller person sits a little closer; both land somewhere sensible without a tape measure. For most adults an outstretched arm to the fingertips is somewhere around two feet, which drops you near the front of every published band on this page.

Treat it as a place to start, not a place to stop. Sit back in your chair as you normally would, reach out, and if your fingertips brush the screen you are roughly in the zone. Then read the actual numbers, because the numbers tell you which direction to move from there — and for a large screen, the direction is almost always back.

What the guidance actually says

OSHA states it as a band, and a generous one:

“the preferred viewing distance is between 20 and 40 inches (50 and 100 cm) from the eye to the front surface of the computer screen”

Twenty inches of latitude. That is not a spec — it is a band inside which most people are fine, and the phrase front surface of the computer screen is worth catching, because it is not eye-to-desk-edge and not eye-to-back-of-monitor. On a chunky panel those differ by a couple of inches.

The AOA, looking at the same setup from the eye side, gives a tighter band:

“Place the computer screen 16 to 30 inches away”

And, in the same breath, ties distance to height in a single sentence that is more specific than either source’s numbers alone: “the computer screen should be 15 to 20 degrees below eye level (about 4 or 5 inches) as measured from the center of the screen and 20 to 28 inches from the eyes”. The two bands do not perfectly coincide — OSHA’s reaches to 40 inches, the AOA’s tops out sooner — and that overlap-but-not-identity is the honest picture. There is a broad zone almost everyone agrees is fine, roughly the low-to-high twenties of inches, and the edges are where reasonable sources differ. Arm’s length sits comfortably inside the agreement.

Distance scales with screen size and resolution

Here is the part the single-number rule cannot handle, and the reason a distance that felt perfect for years can suddenly feel wrong: you bought a bigger screen.

A larger panel subtends a wider angle of your vision at any given distance. Sit a 34-inch ultrawide at the same twenty inches that suited a 24-inch monitor and the edges of the screen fall outside the cone you can take in without turning your head — so you instinctively push it back, toward the far end of OSHA’s band, to see the whole thing at once. Bigger screen, more distance. That is not a rule anyone has to enforce; it is what your neck does on its own once the screen is too close to read comfortably from side to side.

Resolution pulls in the opposite direction, but only as permission, not as instruction. A denser, higher-resolution panel keeps its pixels invisible at closer range, so it allows you to sit closer without the image turning gritty. It does not requireit. A sharp 4K panel that is physically large still wants the distance its size demands — the resolution just means that when you do sit close, the picture holds up. Do not let “it’s high-res” talk you into a distance your screen size argues against.

Height and distance are the same adjustment

Distance is one axis of three, and it does not move independently of the other two. The AOA sentence above already welds distance to height — center of screen about four or five inches below eye level, twenty to twenty-eight inches away — and OSHA does the same from its side: “The top of the monitor should be at or slightly below eye level”, with “the center of the computer monitor… normally located 15 to 20 degrees below horizontal eye level”.

The practical upshot is that you cannot set distance in isolation and call it done. Pull a screen closer and its center rises in your field of view; push it back and the center drops. Get the height right and you have usually nudged the distance, and the other way round. We treat the height and gaze-angle half of this properly in the monitor height guide, which quotes the same two sources on the vertical axis; read the two together and you have the whole target rather than one slice of it.

The 20-20-20 idea, reported not prescribed

People often arrive at “how far away” because their eyes feel tired, and the honest answer is that distance is only part of that story. The AOA’s own contribution here is not a distance at all — it is a break interval, the 20-20-20 rule: “take a 20-second break to view something 20 feet away every 20 minutes”. The logic they describe is that near work makes the eyes work harder over time, and periodically looking far relaxes the focusing effort.

We are reporting that, not endorsing it as our own finding, and we are certainly not turning it into “do this and your eye strain goes away”. It is the AOA’s guidance, it costs nothing to try, and whether it helps you specifically is between you and an optometrist. What it is notis a distance rule — no amount of correct monitor placement is what 20-20-20 is about, and no break schedule fixes a screen parked six inches from your nose.

Desk depth, and where an arm helps or hurts

Now the mechanical part, and the reason this page lives in the monitor arms hub. A distance target is useless if your desk physically cannot deliver it, and shallow desks routinely cannot.

Do the arithmetic before you buy anything. A large screen wants the far end of the band — call it the thirties of inches, eye to glass. Subtract the few inches from your eyes to the desk’s front edge, subtract the panel’s own depth, and what is left is how deep the desk has to be behind the screen. On a 24-inch-deep desk with a big monitor, that sum frequently does not close: the screen is already against the back edge and it is still too close.

This is exactly where a monitor arm gets bought for the wrong reason. An arm buys you height and swing; it does not buy you depth. It clamps at the back edge and reaches forward, which is the wrong direction — it can push a screen closer than you want but it cannot magic up desk that is not there. If your problem is “too close and I have run out of desk”, the fixes are a deeper desk or a smaller screen, in that order, and an arm is a distraction from both. We lay the whole fit calculation out in will a monitor arm fit my desk, and it is the page to read before the credit card comes out.

Where an arm genuinely helps with distance is subtler: by lifting the screen off its bulky factory stand and pulling the panel back flat against the clamp, an arm can sometimes reclaim an inch or two of depth that the stock base was eating — and it lets you slide the screen back to its true limit instead of leaving it parked wherever the base happened to sit. That is a real, modest gain. It is not the same as adding desk, and anyone selling it to you as a distance fix for a small desk is selling you the wrong tool.

A short way to set it, and the verdict

Sit the way you actually sit — not the parade-ground posture you hold for the first ten seconds. Push the screen back to arm’s length as a start. Check that the whole screen is comfortable to read corner to corner without your head moving; if the edges make you turn, go back further, and if a large screen has run out of desk, that is your answer about the desk, not about your eyes. Then set the height so the center sits a little below level, per the height guide, and accept that you have just changed the distance a touch and may need to nudge it again. That loop, done once, beats any number you type in from memory.

The verdict is deliberately unglamorous: there is no single correct distance, there is a band, and arm’s length lands you inside it for most people and most screens. The two things that actually decide whether you can hit the band are screen size and desk depth — not the accessory you bolt on. Get those two right and the distance mostly takes care of itself. Get them wrong and no monitor arm on the market will rescue the geometry.