Ergonomic Desk Setup Guide: Exact Measurements, Angles, and Adjustments for Pain-Free Work

Most ergonomic desk advice has the same problem: it tells you what to adjust but not what number to adjust it to. Sit with your elbows at 90 degrees. Position your monitor at eye level. Keep your wrists neutral. All correct, all useless without the actual measurements. If you are 5’4” or 6’2”, “eye level” lands at very different heights, and so does “elbow level” and “wrist neutral.” A guide that does not give you the numbers is asking you to guess.

This guide gives you the numbers. After several years coordinating workspace setups across distributed teams as a Certified Administrative Professional — and a longer stretch watching the same handful of ergonomic mistakes cause the same handful of injuries — I have a process that calibrates a desk setup from the ground up using specific measurements indexed to your body. We will cover exact heights by user height, joint angles for chair and monitor, a diagnostic table for matching the pain you are feeling to the adjustment that fixes it, and the calibration order that makes all of it work together. This guide is body-level calibration — the measurements indexed to your specific frame, the angles that keep joints out of stress, and the diagnostic logic that turns vague desk discomfort into a single adjustment.

Why Most Ergonomic Setups Fail (and How to Fix Yours)

The standard office desk in North America is 29.5 inches high. That number is not based on average human dimensions; it is a legacy specification from the typewriter era, originally calibrated by furniture manufacturer Humanscale’s research team to the elbow height of a roughly 6’4” man working with a mechanical typewriter that itself sat several inches tall. Everything else has changed in the last seventy years — the typewriter is gone, the average user is not 6’4”, and we no longer hammer keys with extended wrists — except the desk height. Which is why almost every person who sits at a standard desk ends up with their shoulders shrugged upward, their elbows raised above the keyboard, and their wrists extended.

That is the first reason most setups fail: the equipment is calibrated to no one in particular. The second reason is that ergonomics is treated as a static problem to solve once, when the human body is built for movement. The Bureau of Labor Statistics and NIOSH both report that musculoskeletal disorders make up roughly 30 percent of workplace injury and illness cases requiring days away from work, and the dominant pattern is not acute injury — it is the slow accumulation of strain from holding one posture for too long, regardless of whether that posture is technically “correct.”

The framework this guide uses is the opposite of “find the perfect posture.” It is: calibrate the equipment to your body using specific numbers, then change positions deliberately and often. The right posture for the next 30 minutes is whichever one is different from the one you were just in. A chair set correctly for sitting upright at the keyboard is not the right configuration for reading a long document — recline the backrest, lower the monitor, change the angle. Movement is the variable that does more for long-term comfort than any single posture adjustment.

Calibration matters most because it sets the range within which movement is comfortable. A correctly-sized chair lets you shift weight; an undersized one forces you into one rigid posture because every other position is worse. Get the calibration right, then move within it.

Your Ergonomic Measurement Reference Table

Before you touch any adjustment, take one measurement. Sit on a hard chair with your feet flat on the floor, back upright, shoulders relaxed, and upper arms hanging straight down at your sides. Bend your elbows to 90 degrees so your forearms are parallel to the floor. The distance from the floor to the underside of your forearm is your seated elbow height. That number, plus your standing height, calibrates everything else in this guide.

If you cannot measure right now, your seated elbow height is approximately 0.52 times your standing height. A 70-inch (5’10”) person calibrates to about 36 inches floor-to-elbow seated, which puts the keyboard surface at roughly the same height. Your seated desk height should equal your seated elbow height. Your standing desk height should equal your standing elbow height, which is approximately 0.62 times your standing height.

The table below maps every key vertical measurement to user height. These are starting points; refine by feel within plus or minus an inch.

Read the table this way. Seated desk height is the surface your keyboard sits on; if your existing desk is taller than the recommended number, the practical fix is either a height-adjustable desk that drops to your number, or a keyboard tray installed underneath the fixed desk to bring the keyboard down to your elbow height. Chair seat height is the floor-to-top-of-seat dimension that puts your feet flat with your knees at 90 degrees; if your chair will not adjust to your number, a footrest of the appropriate height makes up the difference. Monitor center height is the floor-to-center-of-screen number that puts the top of the screen at roughly eye level for an average eye-to-floor seated distance; expect to refine this within an inch using the close-eyes-open-eyes test below. Standing desk height is your elbow height when standing flat-footed, and it is the number a sit-stand desk should rise to.

The numbers assume an average-proportion body. Long-torso or short-torso users will refine each cell by an inch or two — the principle (elbow height for desk, knee-bent-90 for seat) is what stays constant.

Set Your Chair First — It’s the Foundation of Everything

The order of calibration matters. The chair sets the height your eyes are at; that height determines where the monitor needs to be; the desk needs to be at the right height for your seated elbows, which is determined by where your shoulders end up once the chair is correct. Reverse the order and you will spend the rest of the day micro-adjusting. Start with the chair. The roundup of the best office chairs covers options that genuinely deliver on the adjustment range described below.

The Five Chair Adjustments, In Order

Calibrate these one at a time, top to bottom.

Seat height. Adjust until your feet are flat on the floor and your knees sit at 90 degrees with your thighs parallel to the floor. Use the chair seat height number from your reference table as the starting point. If the chair will not drop low enough, your feet will dangle and pressure will concentrate on the back of your thighs — add a footrest. If the chair will not rise high enough for your legs, you need a taller chair.

Seat pan depth. Slide the seat (if the chair has this adjustment) until there is a 2-to-3-finger gap between the back of your knee and the front edge of the seat, with your lower back against the backrest. This is the single test most people skip and the cause of the most common chair-related complaint — the front edge of the seat pressing into the back of the knees.

Lumbar support height and depth. Raise or lower the lumbar pad until it sits at the natural inward curve of your lower back, roughly at the level of your belt line. Adjust the depth (how far it pushes forward) until you feel firm but unobtrusive contact. You should be able to feel it supporting the curve without it being either invisible or aggressively pushing into you.

Backrest recline. Set the backrest to a slight backward recline — somewhere between 100 and 110 degrees from the seat surface, not bolt upright at 90 degrees. Research from the Karolinska Institute and reproduced by multiple ergonomics labs has shown that a slight recline reduces compressive load on the lumbar spinal discs by roughly 40 percent compared to upright sitting. Lock the recline if the chair allows it, or use a synchro-tilt mechanism that lets the chair move with you while supporting your back.

Armrest height and width. Adjust the armrests until your shoulders are relaxed (not shrugged up) and your forearms rest lightly on the pads with elbows at 90 degrees. Set the armrest width so your elbows sit naturally at your sides, not flared outward. Armrests that are too high force your shoulders up; armrests that are too low let your arms dangle and pull on the shoulder muscles. Both create the upper-back ache most people blame on stress.

What “100-110 Degree Recline” Means in Practice

A vertical seated posture sounds correct because it looks correct, but the physiology disagrees. The lumbar discs experience their highest compressive load when the spine is fully vertical and unsupported. Adding 10 to 20 degrees of backrest recline transfers a portion of your upper-body weight from your spine onto the backrest itself, which is what reduces the disc load. The right recline angle is the one where you can still see your monitor clearly without dropping your head forward. If reclining makes you tilt your head down to read the screen, the monitor needs to come up — do not give up the recline.

The 2-3 Finger Seat Pan Depth Test

Sit fully back in the chair with your lower back against the lumbar support. Reach down behind your knee. You should be able to slide 2 to 3 fingers in the gap between the back of your knee and the front edge of the seat. Less than 2 fingers means the seat is too deep and is cutting into circulation; more than 3 fingers means the seat is too shallow and your thighs are not being supported. The test takes 5 seconds and corrects a problem that otherwise causes leg fatigue, hip tightness, and a constant low-grade urge to scoot forward in the chair.

When Your Chair Will Not Adjust

If your current chair lacks the adjustments above, the workarounds are limited but real. A footrest fixes the seat-too-high problem cleanly. A lumbar roll or small cushion can substitute for a missing lumbar adjustment, though not as well as built-in support. A seat cushion can fix a seat-pan-too-shallow problem partially. A fixed-armrest chair cannot really be corrected — the armrests are either at your elbow height or they are not. If you cannot achieve the basic 90-90-90 posture in your current chair after working through the calibration, the chair itself is the constraint. Every other ergonomic upgrade is downstream of the chair.

Desk and Keyboard Height — Use Your Table Above, Not a Guess

Once the chair is calibrated, the desk has one job: position the keyboard at your seated elbow height so your wrists stay neutral. Use the seated desk height number from your reference table.

The Elbow Hang Test

Sit in your calibrated chair with your hands resting on the keyboard. Your upper arms should hang straight down from your shoulders, your elbows should sit at 90 degrees (or slightly more open, up to 110 degrees), and your wrists should stay straight — not bent up, not bent down, not bent sideways. The keyboard surface should sit at the same height as the bottom of your forearm when you hold this position. If you have to lift your elbows to reach the keyboard, the desk is too high. If you have to drop your elbows below your sides, the desk is too low.

Why Keyboard Feet Should Stay Flat

Almost every keyboard ships with small flip-out feet on the back edge that tilt the keyboard upward toward the user. Do not use them. The flipped-out position extends the wrist backward as you type, which is the opposite of neutral. The Cornell University Human Factors and Ergonomics group, led by Dr. Alan Hedge for many years, has been remarkably consistent on this point — a neutral or slightly negative-tilt keyboard (front edge slightly higher than the back edge) is the lower-strain configuration. Keep the keyboard feet flat against the desk. If you can, use a keyboard tray that tilts away from you (a slight negative angle) rather than toward you.

Keyboard Tray as a Solution for Fixed Desks

If your desk height is fixed and sits above your seated elbow number — and most fixed desks do, because the 29.5-inch standard is too high for most users — a keyboard tray is the cleanest solution. A tray installed underneath the desk surface lowers the keyboard to your actual elbow height while leaving the desktop available for monitors, paperwork, and a coffee mug. The tray should be height-adjustable (so you can fine-tune the elbow alignment), tilt-adjustable (for the slight negative tilt described above), and wide enough to hold both your keyboard and mouse so the mouse stays at the same height as your typing hand. Our coverage of the best ergonomic keyboards walks through tray-friendly keyboards as well.

Palm Rests vs. Wrist Rests — A Distinction That Matters

These two accessories look similar and are often labeled interchangeably. They are not the same thing. A palm rest supports the heel of your hand below the thumb — well away from the carpal tunnel — and is the ergonomically defensible accessory. A wrist rest sits directly under the carpal tunnel at the base of your palm, and pressing the wrist against it during active typing creates a sustained compression load on the median nerve. Research published by Humanscale and corroborated in independent studies has shown this compression can roughly double the internal pressure on the median nerve compared to a floating wrist. The right use of any rest — wrist or palm — is during pauses between bursts of typing, never during active keystrokes. Float the wrists while moving; let them touch the rest while reading. The best keyboard wrist rests roundup covers the better-designed palm-supporting versions.

Monitor Placement — Height, Distance, Tilt, and the Dual Monitor Exception

Monitor positioning is the variable most responsible for neck and upper-back complaints. Three numbers matter: height, distance, and tilt. Two configurations need their own treatment: dual monitors and laptops.

The Close-Eyes-Open-Eyes Height Test

Sit in your calibrated chair facing the monitor at arm’s length. Close your eyes, then look straight ahead. Open your eyes. Your natural gaze should land on the top third of the screen — not the middle, not the top edge, not the bottom. Most people instinctively want to place the monitor lower than this; resist the impulse. The eyes naturally rest slightly downward (the angle is around 10 to 15 degrees below horizontal), and placing the monitor so the top is at eye level and the gaze falls on the upper third matches that natural downward angle while preventing forward head tilt. If your gaze lands on the lower half of the screen, the monitor is too low. The fastest way to raise a monitor to the correct height is a monitor arm, which also frees up desk space underneath. A monitor stand is the simpler and cheaper alternative if only one person uses the desk.

Distance — 20 to 40 Inches, with a Bifocal Caveat

The viewing distance from your eyes to the screen should fall between 20 and 40 inches — roughly arm’s length for most setups. Larger monitors (27 inches and above) push the comfortable distance toward the higher end of that range; smaller monitors (24 inches and below) push it toward the lower end. If the text is too small to read at the correct distance, increase the system font size or the browser zoom rather than moving the monitor closer.

Bifocal and progressive-lens users need a specific adjustment: lower the monitor by 1 to 2 inches below the standard recommendation. The reading correction in bifocal and progressive lenses sits in the lower portion of the lens, so the user instinctively tips the head back to read the screen through the bottom of the lens. The head-back posture compresses the back of the neck and creates a persistent neck strain that gets worse over a workday. A slightly lower monitor lets the user look through the lower reading portion of the lens with the head in a neutral position.

Tilt — 10 to 20 Degrees Backward

The monitor should tilt backward by 10 to 20 degrees, with the top edge slightly farther from you than the bottom edge. This tilt matches the natural downward gaze angle and keeps the viewing distance roughly equal across the full screen surface. A monitor tilted forward (top edge closer to you than the bottom) creates a wedge-shaped viewing geometry where the top of the screen is farther away than the bottom, which forces the eyes to constantly refocus across the surface.

Dual Monitors — Primary-Plus-Secondary vs. Equal-Use

If you use both screens equally — common in video editing, financial work, trading, software development across multiple environments — set the monitors in a shallow V with the inner edges touching at the center, and align the touching midpoint to the center of your body. This way, neither monitor is the “primary” and your head turns roughly equally in both directions. Both monitors should be at exactly the same height (top of screen at eye level), the same distance from your eyes (within an inch), and tilted backward by the same angle. Mismatched heights between the two monitors create a consistent head-tilt asymmetry that produces one-sided neck pain.

If one monitor is primary and the other is a reference screen — and this is the more common setup for most knowledge workers — position the primary monitor directly in front of you with the center of the screen aligned to your nose. Angle the secondary monitor inward at roughly 30 degrees so it sits to the side at the same height. You will turn your head occasionally to use the secondary monitor, but the dominant posture stays neutral.

A pair of monitor arms is what makes dual-monitor geometry actually achievable. A pair of bolted-down monitor stands locks you into the height and distance the stands deliver, and getting two monitors to the same height with stands of slightly different design is harder than it sounds.

Laptop Ergonomics — The Triad Fix

A laptop is the single most ergonomically hostile piece of equipment in common use. The screen and the keyboard are connected, which means they cannot be positioned independently — either the screen is at eye level and the keyboard is too high, or the keyboard is at elbow height and the screen is too low. Either configuration breaks a different part of your body.

The fix is the triad: a laptop stand that raises the laptop screen to eye level, an external keyboard at your elbow height, and an external mouse next to the keyboard. The laptop’s built-in keyboard and trackpad sit unused on the stand while the screen does its job at the correct height. Add a USB-C docking station and the entire setup connects with one cable when you arrive at the desk. The triad converts a laptop from an ergonomic compromise into a fully ergonomic workstation. The cost is modest compared to a chair or a desk, and the impact on neck and shoulder strain is immediate.

Mouse Placement — The Most Overlooked Source of Shoulder Pain

The mouse is the accessory most likely to cause shoulder pain, and the variable most often missed in ergonomic discussions because it does not feel like an ergonomic problem at the moment of use. Shoulder strain from mouse positioning accumulates silently over weeks and surfaces as a one-sided upper-back ache that is hard to pin to a specific cause. The cause is usually one of two things: a mouse positioned too far to the side of the keyboard, or a mouse that requires a sustained grip that strains the forearm.

The Reach Test

Sit in your calibrated chair with your hands on the keyboard. Without moving your shoulder or upper arm, drop your right (or left) hand to where the mouse should sit. The mouse should be within that natural drop — at the same height as the keyboard, immediately to the side, no shoulder reach required. If you have to extend your arm forward, sideways, or both, the mouse is too far away. The dominant cause is a keyboard with a full numeric keypad on the right side, which pushes the mouse 4 to 6 inches further to the right than necessary.

Why Tenkeyless Keyboards Help Mouse Ergonomics

A tenkeyless keyboard — a standard keyboard with the numeric keypad removed from the right side — is the simplest mouse-ergonomics upgrade most users overlook. Removing the keypad pulls the mouse 4 to 6 inches closer to the keyboard centerline, which means the mousing arm no longer has to reach laterally throughout the day. The numeric keypad is genuinely useful for accountants, traders, and other heavy-numeric-entry users, but for everyone else the tenkeyless layout is the better choice. The best ergonomic keyboards roundup covers tenkeyless options designed for this layout.

Vertical Mice and Trackballs

If wrist or forearm pain is the dominant complaint and you have already calibrated the chair, desk, and monitor correctly, the next thing to evaluate is the mouse itself. A standard horizontal mouse keeps the forearm pronated (palm-down) for the entire workday, which puts sustained tension on the forearm muscles. A vertical mouse (held with the palm facing inward, like a handshake position) and a trackball (which keeps the hand stationary while the thumb or fingers do the work) are the two main alternatives. Our best wireless mice roundup covers both formats.

The vertical mouse is the more popular alternative because it requires the least adaptation — the cursor movement still uses the same arm motions as a traditional mouse, just with the hand rotated 90 degrees. The trackball is the more dramatic ergonomic change and the better fit for users with chronic shoulder strain.

Lighting, Glare, and Visual Ergonomics

Lighting is the cheapest ergonomic upgrade in any workspace and the one most directly responsible for end-of-day eye fatigue. Three rules cover most of the cases.

Window Perpendicular Rule

Position your desk so a window is to your side, not in front of you and not behind you. Facing the window puts the bright outdoor scene directly behind your monitor and forces your eyes to constantly recalibrate between two very different brightness levels — that is the dominant cause of the eye fatigue most people blame on screen time in general. With your back to the window, the same window throws glare directly onto your screen. Side light, perpendicular to your line of sight to the monitor, gives you the energizing benefit of natural light without the contrast problem.

Monitor Brightness Matching

Your monitor brightness should roughly match the ambient brightness of the room. A screen set to maximum brightness in a dimly lit room creates an extreme local contrast that fatigues the eyes; a screen set to minimum brightness in a bright room forces the eyes to strain to read the content. Most modern monitors include an ambient light sensor and an auto-brightness setting that handles this automatically. If yours does not, develop the habit of adjusting brightness when the room lighting changes — morning to afternoon, overcast to sunny, lamp on to lamp off. A good adjustable desk lamp with a wide brightness range makes ambient adjustment easier; pair the lamp brightness to the monitor brightness rather than maxing either one.

The 20-20-20 Rule with the Mechanism

The 20-20-20 rule — every 20 minutes, look at something 20 feet away for at least 20 seconds — is endorsed by the American Optometric Association as the simplest defense against digital eye strain. The mechanism is worth understanding, because it explains why the rule is more effective than blinking exercises or eye drops alone. When you stare at a screen at a fixed distance, the small ciliary muscles inside your eye that control focus stay contracted continuously. The fatigue, burning, and blurry-vision symptoms most people associate with long screen sessions are mostly those muscles refusing to relax after hours of sustained contraction. Looking at a distant object releases the contraction and lets the muscles reset. A 20-second break is long enough for the reset and short enough that it does not disrupt focused work. Position your desk so a window or a far wall is in your peripheral view, and the rule becomes effortless to follow.

Diagnose Your Pain — What’s Hurting and What to Fix

This is the table the rest of the guide builds toward. Match the symptom to the most likely cause and the specific adjustment that fixes it. Work down the table to find your strongest current complaint.

Use the table this way. Identify your strongest current symptom and apply the corresponding fix as your single change. Resist the temptation to adjust everything at once — if you change four variables and the pain goes away, you do not know which change mattered, and the same problem will resurface in a slightly different form a month later. Make one adjustment, give it two to three days to see whether the symptom reduces, then either commit to the change or back it out and try the next likeliest fix.

If a symptom does not match anything on the table, or if multiple fixes do not improve a persistent issue, the problem is likely outside the ergonomic domain — a previous injury, an underlying condition, or a sleep-posture problem that masquerades as a desk-posture problem. Ergonomic calibration solves ergonomic problems; it does not solve every body pain. A physical therapist or an occupational health specialist is the right next stop when the table runs out.

Movement, Breaks, and Stretches — Because No Position Is Correct Forever

A correctly calibrated setup makes good posture easier, but no posture is correct for an entire workday. Movement is the variable that does more for long-term comfort than any single static configuration.

The 20-8-2 Framework

Dr. Alan Hedge at the Cornell University ergonomics lab developed a movement cadence specifically for sit-stand desk users: across every 30-minute cycle, spend roughly 20 minutes sitting, 8 minutes standing, and 2 minutes actively moving. Walking to refill water, doing a short hallway loop, or simply standing and stretching all count toward the 2-minute movement window. The cadence captures most of the documented benefits of sit-stand work without the diminishing returns of standing for too long — static standing past 30 to 45 minutes is just as fatiguing as static sitting, which is why pure standing desks underperform compared to alternating setups. A height-adjustable desk paired with a timer or a desk app that nudges you to switch positions makes the cadence sustainable. Pair the desk with an anti-fatigue mat for the standing portion to reduce foot and lower-back fatigue.

Microbreaks vs. Hourly Breaks

Two break patterns work; they serve different purposes. Microbreaks — 1 to 2 minutes every 20 to 30 minutes — release the cumulative muscle tension that builds during focused work. They are short enough not to break concentration on a complex task. Use them to look away from the monitor (the 20-20-20 rule), shift posture, roll the shoulders, or stand briefly. Hourly breaks — 5 to 10 minutes once an hour — are longer recoveries that get you out of the chair entirely. Walk to another room, refill water, do a 30-second stretch sequence, then return. Both patterns reduce strain accumulation more reliably than working through to a single long lunch break and back.

Three Desk Stretches That Help

These take roughly 60 seconds combined and target the muscle groups most affected by desk work.

Wrist extension and flexion. Extend one arm in front of you with the palm facing down. With the other hand, gently pull the fingers back toward your body until you feel a stretch through the forearm; hold for 15 seconds. Reverse — turn the palm up and gently pull the fingers down toward you, hold 15 seconds. Switch arms. This stretches the forearm flexors and extensors that get loaded by typing and mousing.

Neck rolls. Slowly lower your chin toward your chest, then roll your head to the right shoulder, back, left shoulder, and back to chest. Do three slow circles in each direction. Stop if any direction is painful — neck pain is a signal to investigate the cause, not push through. This releases the cervical spine muscles that get strained by monitor-too-low posture.

Shoulder rolls. Roll the shoulders backward in a slow circle five times, then forward five times. Then squeeze the shoulder blades together behind you for 5 seconds and release. This counters the rounded-shoulder posture that desks naturally encourage.

Ergonomic Accessories — What Actually Moves the Needle

Once the chair, desk, and monitor are calibrated, a small number of accessories produce a meaningful additional improvement. Most accessories do not. Here is the rank-ordered list of what is worth buying.

1. Monitor arm. The single highest-impact accessory after the core setup. A monitor arm gets the screen to exactly the right height, lets you adjust depth and tilt independently, and frees up the desk surface underneath. For dual-monitor setups it is essentially required to achieve correct geometry.

2. Footrest. A footrest is what makes a chair that will not lower far enough still work — it raises the floor to where your feet need it. It also helps shorter users at fixed-height desks by giving the feet a stable surface even when the chair is set higher than ideal. Look for one with an angled surface and a non-slip base.

3. Keyboard tray. A keyboard tray installed under a fixed-height desk drops the keyboard to your seated elbow height while leaving the desk surface available for monitors and paperwork. It is the cleanest fix for the standard 29.5-inch-desk problem when buying a new desk is not an option.

4. Anti-fatigue mat. An anti-fatigue mat underneath a sit-stand desk is what makes the standing portion sustainable. Standing on a hard floor for an hour feels fine at the time and produces foot, knee, and lower-back fatigue by the end of the day. The mat distributes weight and lets the small foot muscles shift naturally.

5. Cable management. Cable management trays and sleeves are not strictly ergonomic, but a desk where you can pull the chair forward without snagging cables is a desk where you can actually sit at the correct distance. The before-and-after on cable management is genuinely transformative.

Skip For Most People

A few accessories sell well and either fail to help or actively harm when used wrong.

Wrist rests during active typing. Already covered, but worth repeating in the accessories list — wrist rests used during active typing increase median nerve compression and contribute to carpal tunnel symptoms rather than relieving them. Use during pauses, never during keystrokes.

Lumbar support pillows added to a good chair. A correctly adjustable chair has built-in lumbar support that is already positioned to your spine. Adding a pillow on top either duplicates the support (and pushes you uncomfortably forward) or competes with the built-in adjustment. If your current chair has good lumbar support, leave it alone. If your chair lacks lumbar support entirely, a pillow is a partial fix at best — the longer-term solution is a chair with real built-in support.

Final Calibration — Putting It All Together

Once the equipment is in place, the calibration sequence is always the same. Chair first — height, seat pan depth, lumbar, recline, armrests. Desk next — keyboard at elbow height, mouse beside the keyboard. Monitor next — height, distance, tilt, with the close-eyes-open-eyes test. Lighting last — window perpendicular, brightness matched, lamp positioned.

After the initial calibration, expect to refine for the first two weeks. The configuration that feels right on day one is rarely the configuration that feels right on day fourteen. Make one adjustment at a time, wait two to three days for the body to register the change, and only then evaluate whether to keep it or revert. The diagnostic table earlier in this guide is the reference for which adjustment to try when a new symptom appears.

A correctly calibrated desk does not eliminate the need to move; it makes movement comfortable across a wider range of postures. That is the entire point — not the perfect static posture, but the room to shift between many good ones throughout the day. Get the numbers right, then trust your body to find the rest.