There is no lever under the seat, or there is one and nothing happens when you pull it, and the chair is either stuck at a height that does not fit you or sinking to the floor every twenty minutes.
Picked on published fit specifications, not on hands-on testing. How we pick.
The short answer
If there is genuinely no lever, you have a screw-base chair: hold the base still and rotate the seat clockwise to raise it, counter-clockwise to lower it, with your weight off. If there is a lever and it does nothing, or the chair sinks under you, the gas cylinder has failed - that is a replacement part, not an adjustment, and a standard cylinder fits most chairs.
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Ranked picks with published seat height, seat depth and weight capacity
#ad Seat height and capacity are the manufacturer's published figures, sourced under each pick. We do not publish prices — each button opens the current price on the retailer's own page. Seat depth for every pick is in the spec block below. Seat depth summary: Steelcase Series 1 15.5"–17.75" · Herman Miller Aeron 16"–18.5"
First, work out which kind of chair you have
Two mechanisms are common, and the fix is completely different depending on which one is under you. Tip the chair gently on its side and look at the column between the seat and the base.
Telling the two height mechanisms apart
What you see
Mechanism
How height changes
A smooth metal cylinder, and a paddle or lever under the seat
Pneumatic gas lift
Lift the lever with your weight off to raise, with your weight on to lower
A threaded metal rod, no lever anywhere
Screw base
Rotate the whole seat on the thread - no lever exists to find
A cylinder plus a ring or collar you can turn by hand
Pneumatic with a threaded collar
The collar is a travel stop, not the adjustment - the lever still does the work
If it is a screw-base chair: turn the seat
Older task chairs, drafting stools, many salon and piano stools and a good number of budget chairs use a threaded column with no lever at all. Nothing is broken; the seat is the control.
Stand up. The thread will not turn under load, and forcing it is how threads strip.
Hold the base still with a foot so it cannot spin with you - on castors it will try to.
Turn the seat clockwise to raise it, counter-clockwise to lower it, viewed from above. Standard right-hand thread, several full turns per inch.
Sit, check the fit against your own number, and adjust again. Half a turn is a meaningful amount.
If there is a lever and nothing happens
Three failures account for nearly all of it, and only the first is a fix.
The lever is disconnected, not broken. Some chairs use a lever that presses a small pin on top of the cylinder through a plastic cam. If the cam has slipped off, the lever moves freely and does nothing. Look at the top of the cylinder while someone works the lever: if the pin is not being pressed, reseat the cam. This is the one case worth ten minutes.
The chair rises and then sinks. The cylinder is no longer holding gas. Nothing you do with the lever will change that - it is a sealed part and it has failed.
The chair will not rise at all, with your weight off it. Same diagnosis, further along.
A failed gas cylinder is the cheapest and most standardized component on a chair, and replacing it is genuinely worth doing on a chair you otherwise like - see how long office chairs last for which parts are worth replacing and which mean the chair is done. If the chair is still inside a long warranty, claim rather than buy: Steelcase and Herman Miller publish 12-year cover, and Flokk publishes a lifetime warranty on Capisco gas lifts specifically.
The height is not the only control that is probably wrong
People arrive at this question because the chair does not fit, and height is the only control they know about. It is rarely the only one that is off:
Seat depth. If the front edge presses behind your knees, height will not save it - the seat depth guide has the number.
Lumbar height. Support that lands above or below your curve does nothing at any seat height - where lumbar support should sit.
Armrests. Set too high, they hold your shoulders up all day, which gets felt in the neck.
When the real answer is that the chair does not go low enough
This is common and worth saying plainly. Many task chairs bottom out around 17 inches, and a sitter who needs 15 or 16 has been pulling a perfectly good lever to the end of its travel for a year. If your feet do not flatly reach the floor at the lowest setting, the adjustment is not broken - the range is wrong for you.
Two ways out. A footrest fixes the symptom cheaply and keeps the thighs level. Or buy for the range: Herman Miller publishes 14.4 inches at the bottom of an Aeron A shell, and Steelcase 16.5 inches on the Series 1, both lower than the category norm. Best office chairs for a short person is the full shortlist, and how to measure yourself for an office chair is the five measurements to take before you shop.
The reverse case exists too: chairs that will not go high enough for a tall sitter at a standard desk, which is covered in best office chairs for a tall person.
The picks in full
1. Best for A published height range you can actually check
Steelcase Series 1
If you are replacing a chair because the height was never right in the first place, the specification to insist on is a published seat height - floor to the top of the seat - rather than overall chair height. Steelcase publishes 16.5 to 21.5 inches for the Series 1, which is a five-inch window you can hold against your own knee-crease measurement before you order, plus a functional seat depth of 15.5 to 17.75 inches. The 400-pound rating and 12-year multi-shift warranty mean the cylinder is unlikely to be the part that ends the chair.
Who it fits
Anyone between roughly 5 ft 2 in and 6 ft 1 in who wants to check the number before buying.
Who it does not fit
Anyone needing adjustable lumbar as standard rather than an option.
Published specifications
Seat height
16.5"–21.5"
Seat depth
15.5"–17.75"
Weight capacity
400 lb
Lumbar
Optional adjustable lumbar; weight-activated tension as standard
The commonest reason a height adjustment feels broken is that the chair simply does not go low enough, and the sitter has been pulling a perfectly good lever at the bottom of its travel for a year. Herman Miller publishes a seat height of 14.4 to 19.3 inches on the A shell, which is lower than almost anything else sold, against 15.8 to 22.8 inches on the C. If your feet have never flatly reached the floor, that number fixes it rather than any technique on this page. Gas lifts are covered under the 12-year warranty.
Who it fits
Anyone under about 5 ft 3 in whose feet dangle at their chair's lowest setting.
Who it does not fit
Anyone who wants a padded seat, and anyone who will not check which shell size they need.
Published specifications
Seat height
14.4"–22.8"
Seat depth
16"–18.5"
Weight capacity
400 lb
Lumbar
PostureFit SL or adjustable lumbar pad, both height-adjustable
Sizes
A (seat height 14.4-19.3 in, seat depth 16 in, warrantied to 300 lb), B (14.8-22.8 in, 17 in, 350 lb), C (15.8-22.8 in, 18.5 in, 400 lb)
It is a screw-base chair. Stand up, hold the base still with a foot, and rotate the seat clockwise from above to raise it or counter-clockwise to lower it. It is a standard right-hand thread and takes several full turns per inch. The thread will not move under your weight.
Which way do you turn an office chair seat to raise it?+
Clockwise when viewed from above, with your weight off the seat. Counter-clockwise lowers it.
Why does my office chair keep sinking even though the lever works?+
The gas cylinder has failed and is no longer holding pressure. That is a sealed part, so no adjustment will fix it. A replacement cylinder is a standard commodity component and the cheapest repair on a chair, which is usually worth doing on a chair you otherwise like.
Can I fix a gas lift myself?+
You can replace one. Do not cut, drill, heat or dismantle one - it is a pressurized sealed unit. Avoid the hose-clip trick as well: it locks the chair at one height and scores the cylinder, which makes later removal harder.
My chair is at its lowest setting and my feet still dangle. Now what?+
Then the range is wrong for you rather than the mechanism. A footrest fixes it cheaply; a chair with a lower published seat height fixes it properly. Herman Miller publishes 14.4 inches at the bottom of an Aeron A shell and Steelcase 16.5 inches on the Series 1 - see best office chairs for a short person.
