How to Adjust Your Office Chair

Why the order matters

Seat height changes where your elbows land, which changes the right armrest height. Seat depth changes how far back you sit, which changes where the lumbar pad should be. Backrest angle changes how much weight the lumbar support carries.

Adjust in a random order and every change invalidates the one before it. Adjust in this order and you converge in about ten minutes. Then leave it alone for a week.

1. Seat height, set from your legs and not from your desk

Stand in front of the chair. The top of the seat pan should be at about the height of the crease behind your knee. Sit down and check:

• Feet flat on the floor, whole foot in contact.
• Thighs level, or sloping very slightly downward from hip to knee.
• No pressure under the thighs near the knees.

If your feet dangle: lower the chair. If it will not go lower, you need a footrest, and that is a complete solution rather than a compromise. Your target number is in the seat height table.

If your knees are above your hips: raise the chair. This closes the hip angle and rolls the pelvis backward.

Do not set the chair from the desk. If the desk is too high once the chair is right, raise the chair and add a footrest. If it is too low, raise the desk on blocks. Shrugging your shoulders for eight hours is not a solution.

2. Seat depth

Sit all the way back with your hips against the backrest, then slide two fingers flat into the gap between the front edge of the seat and the back of your knee.

• They fit comfortably: correct.
• They do not fit: the seat is too deep. Find the depth slider - usually a lever on the left or right under the front of the seat, sometimes a knob at the front - and shorten it.
• There is a hand's width of gap: too shallow. Lengthen it if you can.

No depth slider? A firm cushion behind your lower back moves you forward and shortens the effective pan, while adding lumbar support at the same time. Full method in the seat depth guide.

3. Lumbar height

Stand up and run a hand down your spine. Find the point where it curves inward most - for most people that is roughly level with the navel at the front, though it varies with torso length.

Sit down and set the lumbar pad so its fullest part sits at that point. You want contact, not pressure.

• Too high pushes your mid-back forward and arches you unnaturally. Common for short torsos on chairs with limited downward travel.
• Too low pushes on your pelvis and tips you forward off the seat. Common for tall sitters.

No lumbar adjustment? A rolled towel or a strapped cushion at that height does the same job. See best lumbar support cushions.

Some chairs move the whole backrest instead. The Sihoo Doro C300 publishes 18.11 to 21.65 inches of backrest lift and the Hbada E3 Pro publishes 3.15 inches - both achieve the same thing by a different route, and both are worth using.

4. Backrest angle

Set it slightly past vertical - somewhere around 100 to 110 degrees - and lean into it. Sitting bolt upright unsupported puts the whole load through your spine; reclining slightly transfers a real part of it into the chair.

Then move the desk to you rather than leaning forward to reach it. A reclined chair with a monitor too far away produces a person leaning forward in a reclined chair, which is the worst of both.

5. Tilt tension, the control nobody touches

This is a dial or a large knob under the seat, usually at the front, and it sets how hard you have to push to recline. It ships set for whoever the factory had in mind, which is probably not your weight.

Set it so you can rock back with a normal push and the chair holds you without either flopping backward or fighting you. If you never lean back in your chair, this setting is almost certainly why.

6. Armrests, last

Sit with your shoulders relaxed and down, elbows at your sides, forearms roughly horizontal. Now raise the armrests until they just meet your forearms in that position.

• If your shoulders lift to meet them, they are too high. This is the single commonest armrest error and a direct cause of neck and shoulder ache.
• If you have to lean to reach them, they are too low or too far apart. Bring them inward if the chair allows - published width ranges are rare, but the Leap v2 publishes 12.75 to 20 inches, which tells you how much variation matters.
• If they hit the desk, lower them or move them out of the way. Armrests that stop you getting close to the desk are worse than none.

More on the shoulder consequences in best chairs for neck and shoulder pain.

Then the desk, the monitor and the keyboard

The chair is half of it. The OSHA computer workstation guidance covers the rest:

• Top of the screen at or slightly below eye level, at roughly arm's length.
• Keyboard close enough that your elbows stay at your sides.
• Mouse at the same height as the keyboard, not further forward.
• If you work on a laptop on a desk, you are below eye level by definition. A stand and a separate keyboard cost less than any chair and fix more.

Finding the controls

Then leave it alone for a week

A correctly set-up chair frequently feels slightly odd for the first two or three days, because you are loading tissue that had adapted to being unloaded. Judging it on day one leads to endless fiddling and no conclusion.

After a week, if something still feels wrong, change one thing and give it another week. Changing three things at once tells you nothing.