1. Diagonal
Measure only the visible panel from one corner to the opposite corner. Monitor size is normally quoted in inches and excludes the bezel.
Home office screen planner
Monitor size calculator and viewing distance
Enter a screen diagonal and shape to calculate its visible dimensions, a comparison distance and a desk-depth starting point. The 45° to 55° band is a transparent SetupSelect planning model, not a medical or universal ergonomic standard.
How far away should my monitor be?
Comfortable starting range
57–72 cm
Target about 65 cm from your eyes to the screen. The visible panel is approximately 60 × 34 cm, with an estimated 109 pixels per inch.
Desk-depth starting point: approximately 50 cm, assuming your eyes sit around 18 cm in front of the desk edge.
What monitor size fits my distance?
Suggested diagonal range
26–33 inches
Start with commercially available sizes inside or near this range, then check text scaling, stand depth and whether you prefer one large canvas or multiple screens.
Two monitors: measure to the primary screen. Angle the secondary screen inward and avoid placing the join directly in front of you if one display is dominant.
High resolution: more pixels can make text sharper, but operating-system scaling still determines readable text size.
Monitor arms: they can recover desk depth, provided the desk edge and load rating are compatible.
Save or reuse the calculation
Share these inputs or embed the calculator
The link stores only the four calculator inputs in its query string. No result or personal information is sent to SetupSelect by this feature.
Physical size reference
Monitor viewing-distance chart: 24, 27 and 32 inches
Diagonal labels hide the dimensions that use desk and wall space. These figures describe the visible 16:9 panel, calculated from the diagonal; the stand, bezel and casing make the complete monitor larger.
| Diagonal | Visible width | Visible height | SetupSelect comparison range |
|---|---|---|---|
| 24 inches | 53.1 cm | 29.9 cm | 51–64 cm |
| 27 inches | 59.8 cm | 33.6 cm | 57–72 cm |
| 32 inches | 70.8 cm | 39.8 cm | 68–86 cm |
Measure the actual screen
How to measure monitor size correctly
2. Width and height
Measure the visible rectangle separately when checking desk width or a privacy filter. Screens with the same diagonal can have different dimensions when their aspect ratios differ.
3. Complete footprint
Record the casing, stand depth, cable bends and rear clearance as separate measurements. Those figures determine whether the complete monitor fits the desk.
Privacy-screen measurement helper
Accessory makers may specify either the visible panel or the complete filter. Measure your screen yourself and follow the chosen filter's fitting instructions.
Calculated filter rectangle: 60 × 34 cm. This uses the selected monitor's calculated panel size plus the entered coverage on both sides.
How the calculation works
Panel dimensions: diagonal inches are converted to centimetres and split using the selected aspect-ratio triangle.
Distance: panel width ÷ (2 × tan(horizontal angle ÷ 2)). The page shows the distances created by 45° and 55° horizontal angles.
Desk depth: the target eye-to-screen distance minus an 18 cm planning allowance between the eyes and front desk edge, with a 50 cm minimum starting value.
These formulas make different screen shapes comparable. They do not establish a medical requirement or account for eyesight, font scaling, glare, task or mounting position.
Measure the rest of the workstation
Screen distance is only one constraint. Check seated elbow height, chair clearance, desk depth and monitor mounting before choosing products.
Monitor sizing questions
Before choosing a screen
How is monitor size measured?
Measure diagonally across the visible screen area from one corner to the opposite corner. Do not include the bezel or casing. The calculator converts that diagonal into visible width and height for the selected aspect ratio.
How far should I sit from a computer monitor?
There is no single distance that suits every person and task. SetupSelect shows a transparent comparison band based on a 45° to 55° horizontal viewing angle. Use it as a starting point, then adjust text scaling, brightness and distance for comfort.
Does a 27-inch monitor need a deeper desk than a 24-inch monitor?
Usually, because the wider panel creates the same viewing angle from farther away. The stand or arm position, bezel, posture and distance between your eyes and the desk edge also affect the required desk depth.
Should I include the monitor stand when measuring?
Yes. Panel dimensions show how much visual space the screen uses, but the complete setup must also allow for the stand footprint, cables, connectors and any rear clearance required by the manufacturer.
Best next step
Check whether the screen fits the desk
A suitable viewing distance can still fail in practice if the stand, keyboard and cable bends use more depth than the desktop provides.
The calculator provides transparent comparison estimates rather than medical or ergonomic advice. HSE guidance describes the screen as approximately an arm’s length away, with the top near eye level; it does not prescribe the field-of-view band used here. Visual comfort varies, so adjust distance, scaling and brightness and seek professional advice for persistent symptoms. Read the HSE guidance.