A standard desk, an adjustable chair and a monitor on its stock stand do not automatically form a workstation that fits. Comfort depends on how their adjustment ranges work together—and whether they accommodate the user’s legs, arms and eye position.
Setting up a computer workstation correctly is less about following a single diagram and more about matching each component to a specific body. The order matters: set the chair to the legs first, then bring the desk or keyboard to the arms, and only then position the monitor for the eyes. This guide explains the body dimensions behind each step and how body data can improve workstation design for an entire workforce.
Start with the Chair, Not the Desk
A common mistake is to treat the desk as fixed and adjust everything else around it. In practice, the chair should be set first, based on the user’s legs, then the work surface based on the arms, and finally the monitor based on the eyes. Each step depends on a different body dimension.
| Component | Key body dimension | Target relationship |
|---|---|---|
| Seat height | Popliteal height (floor to the underside of the thigh behind the knee) | Feet flat on the floor with thighs roughly horizontal and no pressure behind the knee |
| Seat depth | Buttock-to-popliteal length | Back fully supported with a small gap between the seat edge and the back of the knee |
| Keyboard and mouse height | Seated elbow height | Forearms roughly horizontal, shoulders relaxed, wrists straight |
| Monitor height | Seated eye height | Top of the screen at or slightly below eye level, with a slight downward gaze |
| Monitor distance | Visual needs and screen size | Text readable without leaning forward, typically around arm’s length |
| Leg clearance | Thigh thickness and knee height | Free space under the desk to move the legs and pull in close |
Seated elbow height and seated eye height are measured from the seat surface. Use the adjusted seat height to relate these measurements to keyboard and monitor positions above the floor.
Desk Height: Why One Height Cannot Fit Everyone
A fixed desk may suit some users well. For a shorter user, raising the chair to reach the right elbow height lifts the feet off the floor, which requires a footrest. Without one, the user either dangles their feet, perches on the front of the seat or lowers the chair and works with raised shoulders.
The underlying issue is that popliteal height and seated elbow height do not scale identically across people. A desk height that suits one combination of leg and torso length will not suit another. Height-adjustable desks solve this by letting the work surface follow the arms after the chair has been set for the legs. Where desk height cannot be changed, a footrest or an adjustable keyboard tray may help resolve the mismatch.
Monitor Height: Eye Level and Below
Practical guidance from the Canadian Centre for Occupational Health and Safety (CCOHS) suggests placing the centre of the screen about 15 degrees below horizontal eye level as a starting point, and keeping the top of a tall or portrait-oriented screen no higher than eye level. ISO 9241-5:2024 sets out broader requirements for workstation layout and posture. In practice, this usually places the top line of text at or a little below eye level. A slight downward gaze reduces neck extension and is more comfortable for the eyes.
Three situations deserve particular attention:
- Laptops. A laptop screen used on the desk is almost always too low, leading to sustained neck flexion. An external keyboard with a laptop stand, or a separate monitor, resolves the conflict between keyboard height and screen height.
- Bifocal and progressive lenses. Users of bifocal or progressive lenses may need a lower screen position to read without tilting the head back. Adjust viewing distance to suit the lenses and keep text comfortably readable.
- Multiple monitors. If one monitor is used most often, place it directly in front of the user. If two monitors are used equally, centre the pair in front of the user and angle both screens inward. Keep the screens at the same height to limit repeated neck movement.
Monitor Distance and Screen Size
Viewing distance is often given as roughly arm’s length, but the right distance depends on screen size, text size and the user’s eyesight. A wider screen may need more viewing distance to limit head rotation. Set text size and display scaling so the content remains readable without leaning forward. The practical test is simple: the user should be able to read the screen comfortably while sitting back against the chair, without leaning forward.
Adjusting a Workstation Step by Step: Chair, Desk, Monitor
- Set the chair height so the feet rest flat and the thighs are roughly horizontal.
- Adjust seat depth and backrest to support the lower back without pressure behind the knees.
- Set the work surface or keyboard height so the forearms are roughly horizontal with relaxed shoulders. If the desk is fixed and too high, raise the chair and add a footrest.
- Position the keyboard and mouse close to the body, with the mouse beside the keyboard at the same height.
- Set the monitor height and distance for a slight downward gaze and comfortable reading.
- Check lighting and glare, placing screens at right angles to windows where possible.
Designing Workstations for a Whole Workforce
For facility managers and furniture designers, the challenge is to select products and adjustment ranges that work for every employee, not just the median one. That requires knowing the distribution of popliteal height, seated elbow height and seated eye height in the actual workforce, and in workforces where the same space will be shared.
3D human body data makes this analysis more realistic. Body dimensions do not scale in fixed proportions. People of the same stature can have different combinations of torso, arm and lower-leg lengths, so the chair height that suits one may leave another with a desk that is too high or a monitor that is too low. Checking a workstation against separate percentile values for each dimension can miss these combinations. Evaluating representative body models makes it possible to review seat, desk and monitor adjustment ranges together, and to see which users will need a footrest, which will exceed the range of a monitor arm and which desk height range accommodates the most people in both sitting and standing positions.
Comfo Labs supports workspace planning and office furniture development with this type of body-based evaluation, helping teams define adjustment ranges and setup guidance that fit their users. SIZE LAB provides 3D body-shape data, anthropometric measurements, and representative 3D personas for analyzing a user population’s body dimensions and setting desk, chair and monitor adjustment criteria, and doodll.ai supports concept exploration, design variations, and 3D visualization of workstation configurations.
Computer Workstation Setup Checklist
- Feet: Are both feet flat on the floor or on a footrest?
- Thighs and knees: Is there clearance under the desk and no pressure behind the knees?
- Back: Is the lower back supported by the backrest?
- Arms: Are forearms roughly horizontal and shoulders relaxed while typing?
- Wrists: Are wrists straight, with the mouse close to the keyboard?
- Eyes: Is the top of the screen at or slightly below eye level, at a comfortable reading distance?
- Glasses: Can the user read through the appropriate part of their lenses without tilting the head back?
The best workstation is not the one in the catalog photo. It is the one that has been fitted to the person sitting at it.
WORK WITH COMFO LABS
Designing or specifying workstations for different users?
Talk to Comfo Labs about using body data to define adjustment ranges for desks, chairs and monitor arms.
Frequently Asked Questions
What is the correct monitor height?
For most people, the top line of text should sit at or slightly below eye level so the eyes look slightly downward. CCOHS guidance suggests placing the centre of the screen about 15 degrees below horizontal eye level as a starting point. Users with bifocal or progressive lenses may need a lower screen position.
How far should a monitor be from your eyes?
A common starting point is about arm’s length, but the right distance depends on screen size, text size and eyesight. You should be able to read comfortably while sitting back against the chair without leaning forward. A wider screen may need more distance to limit head rotation; adjust text size and display scaling to keep content readable.
What is the correct desk height for my body?
With the seat adjusted, position the keyboard’s typing surface at or slightly below the user’s elbows, with shoulders relaxed and wrists in a neutral position. If the desk is too high and cannot be lowered, raise the chair and add a footrest, or use a height-adjustable desk or keyboard tray.
In what order should you adjust an office workstation?
Adjust the chair first so the feet rest flat and thighs are roughly horizontal, then set seat depth and backrest. Next set the desk or keyboard to elbow height, place the keyboard and mouse close to the body, and finally set monitor height and distance and check lighting and glare.
Where should the monitor be if I wear bifocals or progressive lenses?
Users of bifocal or progressive lenses may need a lower screen position to read without tilting the head back. Adjust viewing distance to suit the lenses and keep text comfortably readable.
How does 3D human body data improve workstation design?
It helps in three ways. Teams can analyze the distribution of body dimensions such as popliteal height, seated elbow height and seated eye height in their actual user population; check fit against combinations of dimensions as they occur in real people, rather than separate percentile values; and set adjustment ranges and design criteria for chairs, desks and monitors, including who will need a footrest or will exceed the range of a monitor arm.
References
- International Organization for Standardization. (2024). ISO 9241-5:2024 Ergonomics of human-system interaction — Part 5: Workstation layout and postural requirements. https://www.iso.org/standard/86222.html
- Canadian Centre for Occupational Health and Safety. Office ergonomics: Positioning the monitor. OSH Answers Fact Sheets. https://www.ccohs.ca/oshanswers/ergonomics/office/monitor_positioning.html
