Desk and chair height calculator

This desk height calculator turns one number, your height, into four starting points: your chair seat, a sitting desk, a standing desk and the top of your screen. It is built on body measurements of 6,068 adults, and it gives a small range rather than one perfect number, because two people of the same height are rarely built the same.

How the desk height calculator works

The numbers come from ANSUR II, a 2012 survey of US Army personnel in which trained measurers took 94 body measurements on each person (Gordon et al., 2014). Its public release covers 4,082 men and 1,986 women (OPEN Design Lab). From that data we fitted a straight line linking body height to each of four measurements:

• Popliteal height: floor to the back of the knee, sitting with the knees bent at 90°. This sets the chair.
• Elbow rest height: seat to the underside of the elbow, sitting upright with the forearms held level. This sets the desk.
• Sitting eye height: seat to the outer corner of the eye. This sets the screen.
• Standing elbow height: floor to the underside of the elbow, standing with the forearms level. This sets the standing desk.

Everyone was measured in survey shorts, from the floor or footrest up, so the calculator adds an allowance for shoes. The default is 2.5 cm. Furniture studies have allowed 2 cm for trainers and 0.5 cm for slippers (Podrekar Loredan et al., 2022), so set it to zero if you work in socks.

As a cross-check, a chair design study based on US adults measured in 1960 to 1962 put popliteal height at about 25% of body height and elbow rest height at 14% (Sydor & Hitka, 2023). Ours give 24% and 14%.

Then come the rules:

• Chair. No higher than the back of your knee, because the thighs are not suited to carrying your weight (Sydor & Hitka, 2023). OSHA describes the whole sole of the foot on the floor, with the back of the knee slightly higher than the seat (OSHA). Furniture research accepts a seat down to where the lower leg leans about 30° forward (Khoshabi et al., 2020). The calculator aims 2 cm below the back of your knee.
• Sitting desk. Seat height plus elbow rest height, so your forearms are level when your shoulders are relaxed. The UK Health and Safety Executive puts the keyboard just below elbow height (HSE).
• Standing desk. Standing elbow height plus shoes.
• Top of the screen. At or slightly below eye level (OSHA). The calculator aims 2 cm below your seated eye height.

For a 170 cm adult in everyday shoes, that works out at a seat of about 42 cm, a desk of about 66 cm, a standing desk of about 107 cm and a screen top about 118 cm from the floor.

What the numbers cannot know

Proportions vary. Two people of the same height can have different leg, trunk and arm lengths. When we tested the formulas against the survey data, the real seat-to-elbow height that sets your desk was within 2 cm of the estimate for about 6 in 10 people, and within 3 cm for about 8 in 10. That is why every result is a range of plus or minus 2 cm, and why the check on your own body matters more than the number.

The people measured were soldiers, aged 17 to 58, and the dataset’s publishers point out that it does not represent the US civilian population (OPEN Design Lab). Few were shorter than 150 cm or taller than 195 cm, so treat results at either end as rougher.

Everyone sat up straight. From the 1960s US data, Sydor and Hitka calculated that relaxed sitting height is 2 to 5% lower than upright, which is why the screen value sits slightly below eye level.

Furniture is not a ruler. Cushions compress, seats tilt and chair heights are measured in different places. If you wear bifocals, OSHA advises a lower screen so you don’t tip your head back to read.

How to check the result on your own body

Work in this order, because each step depends on the one before. The office chair guide covers each adjustment in more detail.

1. Chair. Sit back with your feet flat on the floor. Your thighs should be roughly level and your knees about the same height as your hips, feet slightly forward (OSHA). HSE suggests a gap of 2 to 3 cm between the front of the seat and the back of your knee.
2. Desk. Let your shoulders drop and your upper arms hang by your sides. With your elbows bent between 90 and 120 degrees, your hands, wrists and forearms should be straight and roughly parallel to the floor, with your elbows at about keyboard height (OSHA). If your shoulders creep up or your wrists bend upwards to reach the keys, the desk is too high for that chair setting.
3. If the desk is fixed and too high, raise the chair until your elbows match the desk, then put a footrest under your feet (OSHA). Enter your desk height and the calculator gives a rough footrest height. A desk that is too low can go up on risers (OSHA).
4. Screen. Sit back and look straight ahead. The top line of the screen should be at about eye level, roughly an arm’s length away (HSE).

On a laptop, screen and keyboard can’t both be at the right height, so HSE suggests a separate keyboard and mouse with the screen raised. See working on a laptop and home office setup.

How high should a standing desk be?

The rule is the same as for sitting: the desk goes at elbow height with your forearms level, so the calculator uses your standing elbow height plus shoes. Raise the screen with it. Cornell University’s ergonomics group warns that if the screen stays where it was, you end up bending your neck to look down at it (Cornell).

Sit-stand desks are one of the better-tested ways to cut sitting time. In a Cochrane review, they reduced sitting at work by about 100 minutes per workday in the first three months, though the evidence was rated low quality (Shrestha et al., 2018). Standing still for hours is not the aim: the same Cornell page says simply standing is not enough, and Cornell’s Alan Hedge suggests a ball-park pattern of 20 minutes sitting, 8 minutes standing and 2 minutes moving (Hedge). Our guide to microbreaks looks at how often to get up.

How high should your monitor be?

Guidelines agree on the principle and differ a little on the detail. OSHA and HSE put the top of the screen at or just below eye level, and OSHA puts the centre of the screen 15 to 20 degrees below your line of sight. Cornell’s guide sits it slightly higher, with your eyes level with a point 2 to 3 inches (5 to 8 cm) below the top of the monitor casing (Cornell). The calculator follows OSHA and HSE, and its number is the top edge of the picture, not the casing.

If you tip your chin up to read the top line, or lean in to read the text, the screen is in the wrong place. How to set up your monitor covers distance, angle, two screens and glasses.

What a good setup can and cannot do

A desk that fits takes away one reason to sit awkwardly, but it does not change how long you sit. To see how those hours add up over a year, try the sitting time calculator, and for a quick look at how your head and upper back line up, the wall posture test. If your neck or shoulders ache by the end of the day, see neck pain from desk work and shoulder pain from computer work.

Bavelu’s desk routines of two to four minutes are designed and filmed by physiotherapists, for the breaks between those hours.