How to Choose an Office Chair for 8 Hours a Day
How to choose an office chair for eight hours a day
Office chairs are sold on features and photographed on their looks, but the things that decide whether one survives — and whether the person in it is comfortable at 4pm — are a certification mark, a weight rating, and three measurements almost nobody checks before ordering.
The short answer. For anyone sitting a full working day, look for AFRDI Blue Tick certification at Level 5 or 6, check the chair is rated for the person's weight, and make sure the seat height, seat depth and armrests all adjust. Standard certification covers users up to about 110kg — above that you need a chair tested to the heavy-duty standard.
The certification that actually means something
Australian and New Zealand office chairs are tested against AS/NZS 4438, the standard for height-adjustable swivel chairs. It covers strength, durability, stability, flammability, workmanship, safety and ergonomics — so it is a genuine performance test, not a paperwork exercise.
What you look for on the product page is the AFRDI Blue Tick, issued by the Australasian Furnishing Research and Development Institute. It confirms the chair has been independently tested for structural durability under load cycling, ergonomic compliance against AS/NZS 4438, stability and safety, and adjustability sufficient to suit around 90% of the adult population.
The levels, and what they're for
| Level | Rated for |
|---|---|
| Level 4 | Office, general keyboard and executive use |
| Level 5 | Heavy duty office, industrial and similar application |
| Level 6 | Extremely severe conditions — police stations, military installations, control rooms, heavy industry |
Levels 4, 5 and 6 are the commercial band; Blue Tick certification is only available at those levels. Level 6 is the benchmark written into many government and education tenders, which is worth knowing if you supply to either.
One honest caveat: AFRDI does not measure comfort. Certification tells you the chair is safe, durable and adjustable enough. Whether it suits the person sitting in it is a separate question that only sitting in it answers.
Weight rating — the spec most people skip
Standard chair certification is regarded as appropriate for users up to about 110kg. That is the assumption baked into the test, and it is not printed prominently on most product pages.
Above that, there is a separate standard — AFRDI 142, the rated load standard for heavy-duty chairs — with certification at 135kg, 160kg and 185kg, tested separately for single-shift and multiple-shift operation. If you are furnishing a workplace rather than a desk, at least some of your chairs should be rated above the standard, and it costs nothing to ask which.
Getting this wrong is the most common cause of premature chair failure. A gas lift or base rated for 110kg carrying more, all day, does not fail immediately — it fails in eighteen months, out of warranty, and usually blamed on the chair being cheap.
The three adjustments that matter
Chairs are marketed on the number of adjustments. Most of them are noise. These three do the work:
1. Seat height
Set so feet are flat on the floor with thighs roughly parallel to it and knees at about a right angle. Then check the desk — if the desk is fixed and too high, raising the chair to reach it leaves feet dangling, and the answer is a footrest, not a different chair. Most gas lifts cover a range; taller and shorter users at the extremes should check the actual range rather than assuming.
2. Seat depth
The most under-specified adjustment on the market and the one that causes the most complaints. You want two to three fingers of clearance between the front edge of the seat and the back of the knee. Too deep and the seat edge presses behind the knee, so the user perches forward and loses the backrest entirely — which is how an expensive ergonomic chair ends up being used like a stool. Look for a sliding seat or seat-depth adjustment on any chair being bought for a range of body sizes.
3. Armrests
Set so shoulders are relaxed and forearms roughly level when typing. Fixed armrests that sit too high push shoulders up all day; too low and they get ignored. Height-adjustable is the minimum worth having; width and depth adjustment matters if the chair pulls up to a desk with a keyboard tray.
Backrest recline and lumbar height are worth having but forgiving — people adapt. Seat depth is not forgiving.
Mesh, foam or leather
| Back type | Suits | Trade-off |
|---|---|---|
| Mesh | Warm offices, long sitting, shared desks | Less lumbar padding; quality varies enormously with tension |
| Upholstered foam | Most offices; the default | Warmer than mesh; foam quality determines how it feels in year three |
| Leather / PU executive | Boardrooms, client-facing offices | Warmest and usually the least adjustable — built to look right, not to sit in for eight hours |
The executive chair point is worth being blunt about: high-back leather chairs are frequently the least ergonomic option in the catalogue. They are the right choice for a boardroom and the wrong choice for someone at a keyboard all day.
The bits underneath
- Castors. Standard castors are made for carpet. On hard floors they roll too freely and mark — you want soft or braked castors, or a chairmat. Getting this wrong is a flooring repair bill, not a chair problem.
- Base. Nylon is standard and fine. Aluminium is stronger, heavier and looks better; it matters most on heavy-rated chairs.
- Gas lift. The most common wear item. Confirm it is replaceable and that spares are available before buying in volume — a chair with an unobtainable gas lift is disposable.
Buying for a workplace, not a desk
Two things change once you are ordering more than one:
Buy adjustable, not sized. A chair that fits one person is a liability the moment they leave. Adjustability is what makes a chair re-deployable, which is the difference between a five-year asset and a two-year one.
Standardise, but not completely. One model across the floor makes spares, servicing and replacement simple. But keep a couple of heavier-rated chairs and at least one with a genuinely wide seat-depth range — the alternative is an urgent one-off order the week someone starts.
And if the chairs are for a workplace, remember that seating sits inside your broader WHS obligations. The chair is one part of a workstation setup that also includes monitor height, keyboard position and how long people sit without moving.
Sources: AS/NZS 4438:1997 (Reconfirmed 2016) Height adjustable swivel chairs, Standards Australia / Standards New Zealand. AFRDI Blue Tick certification levels and the AFRDI 142 rated load standard per published AFRDI certification summaries from Australian and New Zealand seating suppliers. Weight and level descriptions are as published by those suppliers; confirm the certification level and rated load for the specific chair before ordering. This guide is general information for buying purposes and is not ergonomic, medical or WHS advice — for workstation assessments, consult a qualified professional.
Furnishing a floor rather than a desk?
Tell us headcount, whether the floors are carpet or hard, and if anyone needs a heavier rating — we'll put together a chair spec that will still be serviceable in five years.
