acalculator

What desk height do I need?

Take two or three quick measurements in your work shoes. The desk height calculator turns them into seat, desk and monitor heights, using the posture OSHA describes for computer work.

Your numbers

Working
Measurements in
Desk or keyboard height
26.5

Set the desk or keyboard at 26.5 and the top of the monitor at no more than 47.

Chair seat height
17
Top of monitor, at most
47
Desk height in the other unit
67.3
Top of monitor in the other unit
119.4
Screen distance
20 to 40 inches (50 to 100 cm)

Desk or keyboard height: 26.5. Set the desk or keyboard at 26.5 and the top of the monitor at no more than 47.

How to calculate

Works out the chair seat height, desk or keyboard height and monitor height for sitting or standing from your own body measurements, following the OSHA Computer Workstations eTool.

Example with the default inputs (Working Sitting, Measurements in inches, Floor to back of knee 17, Seat to elbow 9.5, Seat to eye 30): Set the desk or keyboard at 26.5 and the top of the monitor at no more than 47.

Method: Sitting: seat = floor to back of knee; desk = seat + seat to elbow; monitor top = seat + seat to eye. Standing: desk = floor to elbow; monitor top = floor to eye.

  • Measure in the shoes you work in. The heights put your thighs level, your forearms level and your eyes at the top of the screen, as the OSHA eTool describes.
  • If the desk cannot be lowered to the desk height, raise the chair and use a footrest.
  • The keyboard sits on the desk surface; with a keyboard tray, the tray takes the desk height.

Machine-readable copies: Markdown, JSON.

Worked examples

Each example is checked against the calculator on every build.

  1. Working Sitting, Measurements in inches, Floor to back of knee 17, Seat to elbow 9.5, Seat to eye 30 gives Chair seat height 17, Desk or keyboard height 26.5, Top of monitor, at most 47, Desk height in the other unit 67.3, Top of monitor in the other unit 119.4.Source: OSHA Computer Workstations eTool (Positions, Chairs, Keyboards, Monitors), https://www.osha.gov/etools/computer-workstations
  2. Working Standing, Measurements in cm, Floor to elbow 106.5, Floor to eye 158 gives Desk or keyboard height 106.5, Top of monitor, at most 158, Desk height in the other unit 41.9.Source: OSHA Computer Workstations eTool (Positions, Chairs, Keyboards, Monitors), https://www.osha.gov/etools/computer-workstations
  3. Working Sitting, Measurements in cm, Floor to back of knee 44, Seat to elbow 23.5, Seat to eye 76 gives Chair seat height 44, Desk or keyboard height 67.5, Top of monitor, at most 120, Top of monitor in the other unit 47.2.Source: OSHA Computer Workstations eTool (Positions, Chairs, Keyboards, Monitors), https://www.osha.gov/etools/computer-workstations

How it works

The OSHA Computer Workstations eTool describes a neutral working posture: feet flat, thighs about level, upper arms hanging with the elbows at about the height of the keyboard, and the top of the monitor at or slightly below eye level. The calculator turns your own measurements into those heights.

Sitting (all measured in work shoes):

  • Chair seat height = floor to back of knee
  • Desk or keyboard height = seat height + seat to elbow
  • Top of monitor, at most = seat height + seat to eye

Standing:

  • Desk or keyboard height = floor to elbow
  • Top of monitor, at most = floor to eye
  • No chair seat height is shown.

Other unit: inches × 2.54 = cm, or cm ÷ 2.54 = inches.

Screen distance: the text "20 to 40 inches (50 to 100 cm)".

Inputs and limits

Each measurement is from 1 to 300 in the unit chosen (inches or cm). Typed values are read as exact decimals and the sums are exact. Every height is shown rounded half up to 1 decimal.

Assumptions

  • The keyboard sits on the desk surface. With a keyboard tray, the tray height is the desk height above.
  • The heights put you in the posture above; the eTool notes that elbows bent anywhere from 90 to 120 degrees also work, so a desk a little lower is fine.

Worked examples by hand

Sitting, in inches: knee 17, seat to elbow 9.5, seat to eye 30. Seat 17 in. Desk = 17 + 9.5 = 26.5 in (67.3 cm). Monitor top at most 17 + 30 = 47 in (119.4 cm).

Standing, in cm: floor to elbow 106.5, floor to eye 158. Desk = 106.5 cm (41.9 in). Monitor top at most 158 cm.

Sitting, in cm: knee 44, seat to elbow 23.5, seat to eye 76. Seat 44 cm. Desk = 44 + 23.5 = 67.5 cm. Monitor top at most 44 + 76 = 120 cm (47.2 in).

Other questions people ask

How high should my desk be?

High enough that the keyboard is at your elbow height with your upper arms hanging and forearms level (OSHA). Sitting, that is the seat height plus the seat-to-elbow height: 17 + 9.5 = 26.5 inches for the default measurements. Standing, it is the floor-to-elbow height.

How high should my chair be?

So that your feet rest flat on the floor and your thighs are about level, with the back of the knee slightly higher than the seat (OSHA). Measure from the floor to the crease behind your knee in your work shoes; the seat goes at that height or a little lower.

How high should my monitor be?

The top line of the screen should be at or slightly below eye level (OSHA). Sitting, that is the seat height plus your seated eye height; standing, your standing eye height.

How far away should my monitor be?

At least 20 inches from your eyes, and OSHA gives 20 to 40 inches (50 to 100 cm) as the preferred range. Move it closer if you lean forward to read.

Why does the calculator ask for measurements instead of my height?

Legs, trunk and arms are not the same share of everyone’s height, so a desk height from body height alone is a rough guess. Two or three measurements of your own body give your own heights, which is what OSHA’s guidance is based on.

My desk is too high and does not adjust. What can I do?

Raise the chair until the keyboard is at elbow height, then support your feet with a footrest, as the OSHA eTool suggests. A keyboard tray below the desk also lowers the keyboard.