Use when setting up or fixing a home-office/desk workstation (new desk, new chair, aching neck/wrists by 3 PM, standing-desk height question) — computes your personal chair/monitor/desk numbers from body height with anthropometric proportions (seat 0.26H, desk 0.415H, seated eye 0.674H, standing elbow 0.63H), checks any monitor size for height/distance compliance, gives the laptop-compromise protocol (riser + external keyboard), maps your specific pain (neck/shoulder/wrist/eye/lower-back) to ranked likely causes with fixes, and prints the posture self-audit + 20-20-20 eye schedule.
Almost every home desk is wrong in the same direction: the desk is too
high for the person (75 cm "standard" suits ~185 cm people — everyone
shorter hunches shoulders), the monitor sits 10-20 cm below eye line
(neck flexion), and the laptop is used flat on the desk (worst of all
worlds). The result shows up as the 3 PM neck ache, wrist tingles, and
eye fatigue that people blame on "too much computer" when it's a
geometry problem with exact numbers.
This skill computes YOUR numbers from your height using standard
anthropometric proportions, then checks your setup against them:
calibrate — height → seat height, desk height, monitor top-edge
height above floor AND above desk, viewing distance, lumbar support
point, keyboard slope. Standing-desk variant included.
monitor — any screen size: does its top edge land at/below your
eye line on your desk? Riser cm needed.
laptop — the laptop compromise protocol (laptop screen + built-in
keyboard is unsolvable; riser + external keyboard is).
Pure stdlib, offline. Guidance reflects widely published ergonomic
practice (OSHA computer-workstation concepts); not medical advice —
persistent pain deserves a clinician.
When to Use
New desk / chair / monitor, or building a WFH corner
"What height should my standing desk be?"
Neck/shoulder/wrist/eye strain after work sessions
Buying decisions: will a 27" monitor be too tall/close for my setup?
Periodic re-check after moving furniture
Don't use for: clinical rehabilitation, existing RSI diagnosis
treatment (see a professional), or industrial/manual-handling ergonomics
(different domain).
The Math (why these numbers)
Proportions of stature H (population-average, seated erect):
Quantity
Fraction
175 cm example
Seat height (popliteal + shoe allowance)
0.26 H
45.5 cm
Sitting elbow above seat
0.155 H
27 cm
Desk (keyboard) height
0.415 H
72.6 cm
Seated eye height (erect)
0.674 H
118 cm
Standing elbow height
0.63 H
110 cm
Viewing distance target
0.38 H, clamped 50-85 cm
66 cm
Consequences worth knowing:
A 75 cm fixed desk forces shoulder shrugging on everyone under ~181 cm.
Eyes sit ~0.26 H above the desk surface → a 24" monitor's top edge on
its lowest stand lands close to eye line; bigger monitors need
LOWERING or more distance, not risers.
Monitor top edge AT or slightly BELOW eye line; screen center 10-15 cm
below eyes; never top edge above eye line.
Desk too high is the #1 home-office error. Fix by raising the
chair to elbow height and adding a footrest — not by lowering the
chair and shrugging.
Monitor directly on laptop-stand height for the built-in keyboard.
When you raise the screen to eye level, the built-in keyboard becomes
unusable — external keyboard + mouse are mandatory, not optional.
Top edge above eye line. Bigger monitors (27"+) frequently need
to be LOWERED or pushed farther away; a 32" at 60 cm distance forces
head extension. Distance target scales with screen size.
Keyboard positive tilt. Little feet folded OUT tilt keyboards
toward you and extend wrists — keep them folded (neutral or slight
negative tilt).
Feet crossed / dangling. Both destroy lumbar position. Footrest
or lower chair + footrest.
Static "perfect" posture. The best posture is the NEXT posture:
vary position; standing desk users should stand 15-30 min per hour,
not all day.
Eyes at arm's length minimum. Closer than 50 cm forces
accommodation strain; if you can't read at 60 cm, that's an eye
exam, not a closer monitor.
Ignoring glare. Screen facing a window = contrast collapse and
adopted neck twist. Screen perpendicular to windows.
Example
text
$ ergo_setup.py calibrate --height 175
PERSONAL NUMBERS for height 175 cm (sitting):
Chair seat height: 45.5 cm (feet flat, knees ~90-100°)
Desk / keyboard height: 72.6 cm (elbows 90-110°, shoulders relaxed)
Monitor TOP edge: 118.0 cm from floor (31.4 cm above desk)
Screen center: ~13 cm below eye line
Viewing distance: 50-85 cm (target ~66 cm)
Lumbar support: at belt line (L4-L5), slight recline 100-110°
Feet: flat on floor or footrest, never crossed
$ ergo_setup.py monitor --height 175 --size 27
27" monitor: panel height ~33.5 cm. On a lowest-stand ~5 cm above desk:
top edge ≈ 39 cm above desk vs eye line 31 cm → 8 cm TOO HIGH.
Fix: lower the stand; if at minimum, increase distance to ~75-80 cm
and tilt slightly up toward eyes.
Verification Checklist
Elbows at 90-110°, shoulders relaxed (not shrugged) at keyboard
Monitor top edge at or slightly below eye line
Screen 50+ cm from eyes (arm's length check: press monitor —
arm fully extended touches it)
