Desk Height Calculator

seat height = stature × 0.25, desk height = stature × 0.25 + stature × 0.158, and eye height above the floor = stature × 0.25 + stature × 0.474

stature

Standing height, without shoes

0.25

Seat height as a fraction of stature — the rule of thumb behind almost every chair

0.158

Seated elbow height above the seat, as a fraction of stature. This is the desk-to-seat gap

0.474

Seated eye height above the seat, as a fraction of stature. Adding the seat height gives eye height above the floor

Use it before buying a desk, or to check whether the one you have is the right height. The result to act on is the desk-to-seat gap rather than the absolute desk height, because that gap is the one ergonomic adjustment you can make without changing chairs: if your chair is fixed, the desk has to match it, and if the desk is fixed you adjust the chair until the gap is right. The number that matters most in use is the top of the monitor, which should land near eye height so the neck stays neutral. What the arithmetic cannot do is fit an individual — it describes the average person of your height, and it says nothing about arm length, torso length or the proportions of your own body.

1. Someone 170 cm tall

   1. Seat height: 170 × 0.25 = 42.5 cm
   2. Desk-to-seat gap: 170 × 0.158 = 26.86, reported as 26.9 cm
   3. Desk height: 42.5 + 26.9 = 69.4 cm
   4. Eye height above the floor: 170 × 0.724 = 123.1 cm

   All three heights land inside the ranges furniture is built to: desks at 680 to 760 mm, seats at 400 to 440 mm, and a desk-to-seat gap of 250 to 320 mm. 170 cm is close to the middle of the range the standard was sized around, so this is the case where the average fits the furniture.

2. Someone 160 cm tall

   1. Seat height: 160 × 0.25 = 40 cm
   2. Desk-to-seat gap: 160 × 0.158 = 25.28, reported as 25.3 cm
   3. Desk height: 40 + 25.3 = 65.3 cm
   4. Eye height above the floor: 160 × 0.724 = 115.8 cm

   65.3 cm is below the 680 mm floor of the standard desk range — the arithmetic is right, and the furniture does not go that low. Below about 163 cm the correct answer is a height-adjustable desk, a keyboard tray, or a footrest with the chair raised. A standard 72 cm desk at a 40 cm seat height leaves a 32 cm gap, which is more than 25.3 cm and pushes the elbows up above the desk.

These are population averages applied to an individual, and the weakest link is the one the desk height depends on. Seated elbow height is only loosely related to stature — the correlation is weak, because most of the difference between a tall person and a short one is leg length, and leg length says nothing about where the elbow ends up when seated. Two people of the same height can differ by more than five centimetres in the height they want their desk. Treat 69.4 cm for a 170 cm person as a starting point to adjust from, and measure your own elbow height if the fit matters. The arithmetic also produces desk heights outside the range furniture is made in: below about 163 cm it gives less than 680 mm and above about 186 cm it gives more than 760 mm, which is a limitation of fixed-size desks rather than a mistake in the calculation. The proportions are adult ones and do not apply to children, whose seating is sized on seat depth and foot support rather than on stature alone. Nothing here accounts for what you actually do at the desk — a keyboard tray, a laptop stand, a second monitor or a drafting table all change the right answer. Finally, a correct desk height does not fix an incorrect posture: the same ratios are compatible with sitting badly if the chair gives no lumbar support or if the monitor sits off to one side.

What is the standard desk height?

Most fixed desks are built between 680 and 760 mm, with 720 to 750 mm the common retail figure for a general-purpose desk. That range is sized around an average adult, which means it fits people in roughly the middle of the height distribution and fits everyone else approximately. The ratio used here (stature × 0.25 + stature × 0.158) gives 69.4 cm at 170 cm and 71.4 cm at 175 cm, both inside that range; it gives 65.3 cm at 160 cm and 77.5 cm at 190 cm, which are outside it in opposite directions.

How do I measure my seated elbow height?

Sit on the chair you actually use, with your feet flat and your back against the backrest. Let your upper arms hang straight down and your forearms rest horizontal — do not lift them. Measure from the top of the seat cushion to the underside of your elbow, keeping the tape vertical. That distance is the desk-to-seat gap you want, and it is the number the desk height depends on. It is worth doing because the ratio on this page is only an average: measured directly, it is exact for you, and it takes about a minute.

Should I adjust the chair or the desk?

Set the chair first, then make the desk match. Seat height is fixed by your legs — feet flat, thighs roughly horizontal, no pressure behind the knees — and once that is right, the desk has to come to your elbows rather than the other way round. If the desk cannot move, raise the chair to the right height and add a footrest, which is the standard fix when a desk is too tall for the person using it. If the desk is too low and cannot be raised, a keyboard tray or risers work, but the monitor then needs to come up as well.

How high should my monitor be?

The top of the screen should sit at or slightly below eye level, so that you look very slightly downward at the middle of it and your neck stays neutral. This page gives seated eye height above the floor — 123.1 cm for someone 170 cm tall — and that is the height to aim the top edge at. If you wear progressive or bifocal lenses you will want the monitor lower, because you read through the bottom of the lens; if you use a laptop without a stand, the screen will be well below this and the fix is a stand plus an external keyboard rather than raising the whole setup.

Do these ratios work for children?

No, and the failure is not a small one. Children are not scaled-down adults: their proportions change as they grow, and the dimensions that decide whether a chair fits are seat depth and whether the feet reach the floor, not stature alone. A child at a desk sized by this formula would have their feet dangling and the desk at chest height. Children's furniture is sized by age and height bands against its own standards, and a footrest matters more than the exact desk height.

• Office ergonomics — working heights, seating and the adjustment order — Canadian Centre for Occupational Health and Safety
• Computer Workstations eTool — workstation heights and chair adjustment — Occupational Safety and Health Administration, US Department of Labor