Chair Armrest Height and How to Set It for Relaxed Shoulders

By mid afternoon there is a dull ache across the top of your shoulders, and when you finally notice it, you realise your shoulders have been hovering near your ears for hours. You check your monitor height. Fine. Your keyboard. Fine. Then you look down and see your elbows planted on armrests that sit a good four centimetres too high, propping your whole upper body into a permanent shrug.

Chair armrests are the most ignored adjustment on most office chairs. People set the seat height once, maybe the lumbar, and leave the arms wherever they arrived from the factory. In my own flat I have rearranged the desk eleven times in three years, and the armrest setting has caused more trouble than any monitor or keyboard I have tried.

What armrests are actually for

Armrests have one job: take some weight off your shoulders when your arms are not doing anything demanding. Each arm weighs roughly 5 to 6 percent of your body weight. For a 70 kilogram person, that is around 4 kilograms per side hanging from the neck and shoulder muscles all day if nothing supports it.

When armrests sit at the right height, your forearms rest lightly and the trapezius muscles across the top of your shoulders can relax. When they sit too high, they push your shoulders up. When they sit too low, you either lean sideways to reach them or ignore them completely, and your shoulders carry the full load again.

The key word is lightly. Armrests should support, not hold you up.

How to find the right height in two minutes

Set your seat height first, with feet flat and thighs roughly level, because armrest height only makes sense relative to the seat. If you have not done that yet, start with matching your chair height to your desk and come back.

Then sit back fully, let your arms hang loose at your sides, and bend your elbows to about 90 degrees with your upper arms vertical. Have someone measure the distance from the seat to the underside of your elbow, or do it yourself with a tape measure against the chair. That is your target armrest height, measured from the seat surface to the top of the pad.

For most adults it lands between 18 and 27 centimetres. I measure 21. My partner, who is 12 centimetres taller and shares the desk on Fridays, measures 24.

Now raise or lower the armrests until the pad just touches your forearm when your shoulders are fully relaxed. A useful check: shrug hard, then let go. Your shoulders should drop all the way without the armrests stopping them. If they hit the pads before they settle, the arms are too high.

Matching armrests to the rest of the desk

Armrest height and keyboard height are linked. Ideally your forearms are near level with the keyboard and the armrests sit just below that line, so you can type without lifting off them and without pressing down into them.

If your keyboard is the real issue, the measurements in our keyboard height guide will tell you where it should sit, and the armrests follow from there.

The advice I disagree with: armrests flush with the desk

Plenty of setup guides say armrests should be exactly level with the desk surface, so your forearms glide from one to the other. It sounds tidy, and it photographs well. In practice, on most fixed-height desks, it causes two problems.

First, a flush armrest often stops you pulling the chair in far enough. You end up sitting 10 or 15 centimetres back from the desk and reaching forward for the keyboard, which rounds your upper back. Second, the standard desk height of about 73 to 75 centimetres is too tall for many people. Setting armrests flush with it means setting them too high for your body.

I tried flush armrests for a month on my old 74 centimetre desk. My shoulder ache was worse by the end of the first week. Dropping the armrests 3 centimetres below the desk edge and letting them slide under it fixed most of the problem within days, though I will admit my sample size is one person and one chair.

Your body sets the armrest height. The desk only decides whether you need to lower the desk or raise the keyboard to meet it.

When to use them, and when to move them away

Armrests help most during reading, calls, video meetings and mouse work with small movements. They help less during heavy typing, where many people type better with forearms floating just above the pads. Some people also find armrests get in the way of a mouse placed far to the right.

If your chair has 3D or 4D armrests, use the extra adjustments. Slide the pads forward for reading, swing them inward for typing so your elbows stay close to your body, and push them back when you need to pull right up to the desk.

If your armrests do not adjust at all and sit too high, removing them is often better than living with them. Most chairs use two or four bolts underneath. Keep the parts in a bag taped under the seat in case you move house or sell the chair.

On a shared desk, write each person's setting on a strip of masking tape stuck to the armrest post. Ours says 21 cm and 24 cm, each with the number of clicks up from the lowest position written next to it. It takes ten seconds to switch on a Friday morning, and nobody spends the afternoon wondering why their neck hurts.

One thing to do today

Do the shrug test now. If your shoulders cannot drop all the way, lower the armrests one notch and work for an hour. Repeat until the ache across the top of your shoulders stops being the thing you notice at four o'clock. More fixes like this are in the ergonomics section.

FAQ

How high should chair armrests be?

Level with or just under your elbows when your shoulders are relaxed and arms bent at about 90 degrees. For most adults that is 18 to 27 cm above the seat.

Should armrests touch the desk?

Not necessarily. Many setups work better with armrests slightly below the desk edge so the chair can slide in close.

Is it bad to work without armrests?

Not if your keyboard and mouse are at the right height and you take regular breaks. Armrests that sit too high are worse than none.

Why do my shoulders hurt even with armrests?

Usually the armrests are too high, lifting your shoulders, or too far apart, so your elbows splay outward.