Set your chair and desk from your own height

Tall Spine editorial deskUpdated September 2026Built from ANSUR II means plus CCOHS, OSHA and Cornell guidance
Short answer

Set the seat from your legs: seat height equals the floor to the crease behind your knee, about a quarter of your height. Then set the desk from your elbows, at seated elbow height. When a fixed desk is too high for both, raise the chair and add a footrest of the difference. The footrest is the standard fix.

Almost every desk-height argument is really two arguments: one about your legs and one about your elbows. They have different answers, and the fix when they conflict is a footrest.

On this page
  1. The order that works
  2. Seat from your legs
  3. Desk from your elbows
  4. The monitor
  5. The lumbar support
  6. Worked numbers by height
  7. If you stand instead

The order that works

  1. Seat height, from your legs.
  2. Footrest, if the seat had to go higher than your legs want.
  3. Desk height, from your elbows. Then the monitor, from your eyes.

Step 1: seat height from your legs

One dimension sets your seat height: popliteal height, the floor to the crease behind your knee, measured standing in the shoes you work in. CCOHS gives a rule of thumb that holds up well: the optimal seat height is about one quarter of your body height, with the caveat that the torso-to-leg ratio varies widely.

In the ANSUR II survey the means were 38.9 cm for women and 43.4 cm for men, against mean heights of 163 cm and 176 cm. That is 24 to 25 percent of stature.

  1. Stand in front of the chair and set the height until the seat top sits just below your kneecap. This is the CCOHS test and it tracks popliteal height closely.
  2. Sit down. Feet flat, a clenched fist of clearance between the seat edge and the back of your calf.
Thigh pressure is the tellIf the seat edge presses into the back of your thighs, the seat is too high or too deep. Tingling after an hour is a circulation problem caused by the seat edge, and no cushion fixes it.

Step 2: desk height from your elbows

Desk height has nothing to do with your height above the floor and everything to do with your elbows. Sit with your shoulders relaxed and forearms roughly horizontal. The keyboard surface goes at that height, so your elbows sit near 90 degrees and your wrists stay straight. CCOHS gives the same rule for a standing desk.

In ANSUR II the elbow rest height above the seat averaged 22.1 cm for women and 23.1 cm for men, about 13 percent of body height. Add that to your seat height and you have the target.

This is where the standard office desk causes trouble. A typical fixed desk is 73 cm high. For a 175 cm person the correct keyboard height is about 66 cm, so reaching 73 cm at the elbows needs a seat near 50 cm, some 7 cm higher than their legs want.

The footrest rule in one line

Seat height needed = desk height minus your elbow height. If that is higher than your leg length, raise the chair to it and put the difference under your feet. Mayo Clinic gives the same instruction for a desk that cannot be changed.

Step 3: the monitor

What Target Source
Top of the screen At or slightly below eye level Mayo, CCOHS
Centre of the screen About 15 degrees below the horizontal line at your eyes, no more than 30 CCOHS
Distance from your eyes 50 to 100 cm; Cornell’s test is that your fingertips almost touch the screen with your arm out Mayo, Cornell

Cornell adds a warning in the other direction: looking up above the horizontal is tiring, and a monitor that is too high is worse for your neck than one slightly too low.

Step 4: the lumbar support

With the seat and desk right, the support has one small job: fill the hollow in your lower back so it stays against the backrest instead of sagging away from it. That hollow sits 24.8 cm above the seat for women and 25.3 cm for men, and it is only 2.2 to 2.5 cm deep. OSHA’s guidance is a backrest with height-adjustable lumbar support, or a rolled towel if the chair has none. The method is in How to use a lumbar support cushion.

Worked numbers by body height

Arithmetic from ANSUR II means, not a prediction about you.

Seat at 24.3 percent of height, elbow height 13.3 percent, standing elbow 61.2 percent, seated eye height 45.2 percent.

Your height Seat height Desk or keyboard Desk standing Top of monitor
160 cm (5 ft 3) 39 cm 60 cm 98 cm 111 cm
170 cm (5 ft 7) 41 cm 64 cm 104 cm 118 cm
175 cm (5 ft 9) 43 cm 66 cm 107 cm 122 cm
183 cm (6 ft 0) 44 cm 69 cm 112 cm 127 cm
190 cm (6 ft 3) 46 cm 72 cm 116 cm 132 cm

The desk and chair height calculator does this for your height and your measured leg length, and returns the footrest figure for a desk you already own.

If you stand instead

  1. Set the desk to your standing elbow height with your arms hanging relaxed. For a 175 cm person that is about 107 cm.
  2. Raise the screen with the desk. If the monitor stays on the desktop while the desk rises, the screen ends up below your eye line. Cornell flags this directly: you need a monitor arm or a stand.
  3. Alternate rather than choose. The CSA Z412-17 standard, summarised by CCOHS, recommends alternating between sitting and standing because no single posture suits a person for an extended period.

On how much it helps: a Cochrane review of 34 studies found low-quality evidence that sit-stand desks reduce sitting time in the first year of use, and none beyond that. A separate review of 10 studies found the evidence insufficient to show they reduce the intensity of low back or upper back symptoms.

If the furniture is fixed, the fixes in order of value are a footrest, blocks under the desk legs, a riser under the screen, and a keyboard tray.

Questions people ask

How do I set my chair height to my body?
Stand in front of the chair and set the height until the highest point of the seat is just below your kneecap, which matches popliteal height. Then check your feet are flat with a clenched fist of space behind your calf.
What height should my desk be?
Seated elbow height: your seat height plus about 13 percent of your body height, so roughly 66 cm for a 175 cm person. A standard 73 cm desk is too high for most people at a leg-correct seat height.
What if my desk is too high and cannot be adjusted?
Raise your chair until your elbows reach the desk, then put the difference under your feet. Mayo Clinic gives this instruction explicitly, and CCOHS recommends an adjustable chair plus a footrest for a fixed desk.
Which comes first, the chair or the desk?
The chair. Seat height is set by your legs and cannot be negotiated, while desk height can be reached with a footrest or a keyboard tray.
Should I stand instead of sit?
Alternate rather than choose. Standing all day is more tiring and loads the legs, feet and circulation, and Cornell notes that fine motor performance is worse standing. CCOHS summarises CSA Z412-17 as recommending alternation.

Sources

  1. NC State University Ergonomics Center. ANSUR II anthropometric data tables — multisite.eos.ncsu.edu/www-ergocenter-ncsu-edu/wp-content/uploads/sites/18/2016/06/Anthropometric-Detailed-Data-Tables.pdf
  2. CCOHS. Office Ergonomics: The Ergonomic Chair — www.ccohs.ca/oshanswers/ergonomics/office/chair.html
  3. CCOHS. Office Ergonomics: How to Adjust Office Chairs — www.ccohs.ca/oshanswers/ergonomics/office/chair_adjusting.html
  4. CCOHS. Office Ergonomics: Sit/Stand Desk — www.ccohs.ca/oshanswers/ergonomics/office/sit_stand_desk.html
  5. CCOHS. Sitting Position: Basic Requirements (CSA Z412-17) — www.ccohs.ca/oshanswers/ergonomics/sitting/sitting_basic.html
  6. CCOHS. Office Ergonomics: Positioning the Monitor — www.ccohs.ca/oshanswers/ergonomics/office/monitor_positioning.html
  7. OSHA. Computer Workstations eTool: Chairs — www.osha.gov/etools/computer-workstations/components/chairs
  8. Cornell University Ergonomics Web. Workstation ergonomics guidelines — www.ergo.human.cornell.edu/ergoguide.html
  9. Mayo Clinic. Office ergonomics: your how-to guide — www.mayoclinic.org/healthy-lifestyle/adult-health/in-depth/office-ergonomics/art-20046169
  10. Shrestha N, et al. Interventions for reducing sitting at work. Cochrane 2018 — www.cochrane.org/evidence/CD010912_workplace-interventions-reducing-sitting-work
  11. Cochrane. Interventions for increasing standing or walking. CD012487 — cochrane.org/CD012487/OCCHEALTH_workplace-interventions-increasing-standing-or-walking-decreasing-musculoskeletal-symptoms-sedentary-workers

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