How to Adjust Your Ergonomic Chair So It Feels Right for You

Two people can sit in the same ergonomic chair—one feels fine all day, the other gets a sore back in half an hour. The difference is usually not the chair, but whether it’s adjusted for that person. Ergonomic chairs are made to be adjusted. Only when you set it up for yourself will it feel comfortable and support you properly.

Why you need to adjust it

What is an ergonomic chair, really? Not a fixed shape that's supposed to suit everyone — it's a set of adjustment points that only do their job once you've actually set them for your own height, leg length and back shape. The factory settings can't fit everyone. Sitting without adjusting is like wearing shoes you never tried on—sooner or later it gets uncomfortable. Spend a few minutes following the steps below, and your chair will feel much better every day.

Step 1: Seat height

When you sit, your feet should rest flat on the floor. Your thighs should be roughly level with the ground, knees at about 90°. If the seat is too high, your feet dangle and your thighs get pressed. If it’s too low, your knees go above your hips and you lean forward. Most chairs have a lever under the seat or on the side to change height. Set it, then lock it if there’s a lock.

Step 2: Seat depth

With your back against the backrest, leave about a fist’s width between the back of your knees and the front edge of the seat. Too shallow and your thighs don’t get enough support. Too deep and the seat pushes behind your knees, which can hurt circulation and make you slouch. If your chair has a depth adjustment, slide the seat until you get that fist-sized gap.

Step 3: Lumbar support

The lumbar pad should fit the curve of your lower back—right in the small of your back, not too high and not floating in the air. If it’s height-adjustable, move it up or down until it feels supportive but not pushing too hard. If you can change how far it sticks out, set it so it gently supports your back. This helps reduce strain when you sit for a long time.

This is the single step that matters most if you're after an ergonomic lower back support chair rather than just a comfortable seat. The exact process depends on what your chair offers: Smile's 4-level system needs you to pick a level and a Stretching or Leisure mode, Spencer's four-zone TPU band needs each zone set individually, and the S5's waist-and-back linkage adjusts itself as you move, so there's nothing to manually reset once it's fitted.

Step 4: Armrests

When your arms rest on the armrests, your elbows should be at about 90°. The armrests should be level with your desk or a bit lower, so your shoulders stay relaxed when you type or use the mouse. Too high and you shrug; too low and your arms hang. If the armrests move forward, back, or sideways, set them so your arms sit naturally without reaching or squeezing in.

Step 5: Headrest (if you have one)

The headrest is for supporting the back of your head or your neck when you lean back. It should touch your head gently—don’t set it so it pushes your head forward. Adjust the height to the back of your head or just under your neck, and the angle so it matches how you like to relax. If you don’t use it, move it up or back so it doesn’t get in the way.

A headrest set too far forward is one of the more common, overlooked causes of ergonomic chair neck pain — it pushes your head into a forward-craned position instead of supporting it, which defeats the purpose entirely.

Step 6: Backrest angle and tension

If your chair has a recline and tension control: sit a bit more upright when you work so you can see the screen and write easily. When you take a break, lean back a little so your back is supported. Set the tension so the chair doesn’t tip back too easily, but still returns when you sit up. Not too loose, not too stiff.

Summary

The point of an ergonomic chair is that you can adjust it—everyone is different, and it only feels right when it’s set for your body. When you get a new chair, go through these six steps once. Then tweak a bit over the first week or two until it feels just right. After that, you’ll sit more comfortably and with better posture.

Frequently Asked Questions

How do I know if my ergonomic chair posture is actually correct?

Feet flat, knees near 90°, a fist-width gap behind your knees, lumbar support sitting in the small of your back, elbows near 90° on the armrests, and a headrest that touches without pushing your head forward. If all six line up, your posture is set correctly — go through the six steps above in order if any of them feel off.

I just bought a new ergonomic chair — where do I start?

Seat height first, then depth, then lumbar, then armrests, then headrest, then recline tension — in that order. Each step assumes the previous one is already set, so doing them out of order usually means redoing one of the earlier steps anyway.

My chair doesn't have all these adjustments. Does that mean it's not ergonomic?

Not necessarily, but it does mean it can only fit you within a narrower range. Entry-level chairs like the A19 skip the headrest and use a fixed lumbar curve rather than an adjustable one, which works fine for some body types and less well for others. Models like the S5 or Smile and Spencer add the adjustment points this guide covers precisely because more adjustment range means a better fit for more people.