We say it in nearly every guide on this site: if you spend money on one thing in a home office, spend it on the chair. But "buy a good chair" is useless advice without knowing what good means. Strip away the marketing and it comes down to five adjustments, one quick test, and a strong argument for buying used.

The five adjustments that matter

"Ergonomic" isn't a property a chair has — it's a fit between the chair and your body. That means adjustability. These five, in order of importance:

  1. Seat height. Non-negotiable. You need your feet flat on the floor with knees around 90°, and your elbows level with the desk. Any chair that can't reach your desk height is the wrong chair.
  2. Lumbar support. The backrest must meet the inward curve of your lower back. Adjustable height (or depth) here is worth a lot, because backs differ far more than seats do.
  3. Seat depth. You should be able to sit right back against the backrest and still fit two or three fingers between the seat edge and the back of your knees. Too deep and the edge cuts off your circulation; too shallow and you get no thigh support.
  4. Armrests. They should let your shoulders drop and your forearms rest lightly while typing. Fixed armrests that force your shoulders up are worse than none at all — if they're in the way, remove them.
  5. Recline and tilt. Being able to lean back and lock, or move freely, matters more than it sounds — no posture is good for eight hours, so a chair that lets you shift is doing real work.
Set the chair first, then everything else

Chair height drives desk height, which drives monitor height. Get the chair right before you adjust anything else — the full sequence is in our ergonomic home office guide.

The 60-second showroom test

Whether you're in a shop or trying a second-hand chair in someone's hallway, run this:

  • Sit all the way back. Does the backrest meet your lower back's curve? Can you feel support without a cushion?
  • Check the knee gap. Two or three fingers between the seat edge and your knees.
  • Drop your arms. Do your shoulders relax, or are the armrests pushing them up?
  • Adjust the height. Feet flat, knees ~90°, and the gas lift should hold — a chair that slowly sinks is a chair with a dead cylinder.
  • Lean back. Does the recline feel supportive, or does the whole thing feel flimsy?

A chair that fails the knee gap or the shoulder test won't be fixed by getting used to it.

What you can safely ignore

  • Headrests — pleasant when reclining, irrelevant while you work, and they push your head forward on some chairs.
  • "Gaming" styling. Racing-bucket seats look dramatic and are often less ergonomic: the raised side bolsters restrict how you sit, and fixed armrests are common.
  • Lever count. Ten adjustments you never touch beat none — but five you actually set beat ten you don't understand.
  • Brand mythology. A famous designer name doesn't guarantee it fits your body, and plenty of unglamorous commercial chairs are excellent.

Buying second-hand (the smart move)

This is where the real value is. Commercial-grade chairs were built for eight hours a day, five days a week — mechanisms, foam density and warranties to match. The office-clearance and used-furniture market is full of them at a fraction of retail, and a ten-year-old good chair usually beats a brand-new budget one.

When buying used, check: the gas lift holds height (the most common failure, and cheaply replaceable), the foam hasn't compressed flat in the seat, the casters roll on your floor type, and every lever still does something. Fabric wear is cosmetic; a dead cylinder or crushed foam is not. This is the same logic as our budget home office guide: spend where your body meets the setup, save everywhere else.

Mesh, foam and the kneeling-chair question

Mesh breathes well and suits a warm room, but a cheap mesh seat can dig in at the front edge. Moulded foam is more forgiving over long sittings if the density is decent — poor foam flattens within a year. Judge the specific chair, not the material category.

Kneeling chairs, saddle stools and balance balls aren't a straight upgrade. They shift load rather than remove it, offer no back support, and get tiring for full days. They work best as an alternative seat you rotate to for an hour — the same "keep changing position" principle behind sit-stand desks.

Buy for fit, not features. Five adjustments, one 60-second test, ideally bought used — and then remember that even a perfect chair wants you to get out of it every hour.

Frequently asked questions

What makes a chair ergonomic?

Adjustability, not marketing. A genuinely ergonomic chair lets you set seat height, has support for the curve of your lower back, a seat depth that leaves a gap behind your knees, and armrests that let your shoulders relax. If it can't be adjusted to your body, it isn't ergonomic for you.

How much should I spend on an office chair?

Spend as much as you can justify on this one item, but buy second-hand to stretch it. A used commercial-grade ergonomic chair often costs a fraction of its original price and outperforms a new budget chair, because the mechanisms and foam were built for eight hours a day.

Are mesh or foam office chairs better?

Neither is universally better. Mesh breathes well and suits warm rooms, but a cheap mesh seat can feel hard at the edges. Moulded foam is more comfortable for long sittings if the density is good. Judge the specific chair, not the material.