What is an ergonomic chair?

What the label should mean in practice

An ergonomic chair should let you set it so your feet rest flat on the floor or a footrest, your thighs are supported without the seat edge pressing behind your knees, your lower back is supported, and your arms can rest without lifting your shoulders. The HSE display screen equipment guidance describes a working posture with forearms roughly horizontal at the keyboard, and the chair is what makes that possible.

To do that for many different people, a chair needs adjustments. The more of these it has, and the wider their range, the more people it can fit.

• Seat height, ideally with a range that suits your knee height
• Seat depth, via a sliding seat or a choice of sizes
• Lumbar support that moves up and down, ideally in depth too
• Back angle with tilt lock and tension, or a weight-activated tilt
• Armrests that adjust in height, and ideally depth and pivot
• A stable five-star base and a load rating that suits you

Sizes and ranges in centimetres

Adjustments only help if their ranges suit you. Seat height ranges on the chairs in our guides run from roughly 45 to 58.5 cm at the top end; tall users need a higher range and shorter users a lower one. Seat depth slides commonly offer 5 to 6 cm of travel, and some listings give the full range, such as 33 to 43 cm on the ProtoArc EC200.

Some makers quote a user height range instead, such as 163 to 195 cm for the ProtoArc EC300 or 160 to 192 cm for the Tonfary 819. These are a useful starting point but not a guarantee, because leg and back length vary between people of the same height.

Standards: BS EN 1335 and BIFMA

BS EN 1335 is the European standard for office work chairs. It covers dimensions, safety requirements and test methods, so a chair that meets it has adjustment ranges and stability within set limits. Listings for the ProtoArc and Elabest chairs in our guides cite EN 1335. EN 16955 covers gas lift cylinders, and EN 12520 covers strength and durability of seating more generally.

BIFMA X5.1 is an American standard for strength and durability, widely cited by chair makers. Certification to any of these is a good sign of build quality, but it does not prove a chair will fit you. Always check the actual ranges.

How to choose one

Measure your seated knee height (floor to the back of the knee in your usual shoes) and compare it with the seat height range. Measure thigh length from the back of your bottom to the back of your knee and compare with seat depth. Check the load rating. Then decide which extras matter: mesh for a warm room, a headrest if you lean back, a footrest if you rest at the desk.

Do not pay for features you will not use, and do not accept missing basics. A chair with seat depth, movable lumbar and adjustable arms beats one with RGB lighting and fixed arms.

See our ergonomic chair picks →

Setting it up

Even the best chair needs setting up. Start with seat height, then seat depth, back angle, lumbar and arms. Our step-by-step chair set-up follows the HSE order, and our ergonomic vs normal chair comparison shows how two chairs differ on the checklist.

Frequently asked questions

What does ergonomic chair mean? A chair designed to adjust to fit the user, with seat height, seat depth, lumbar, back and arm adjustments.

Is every chair labelled ergonomic actually ergonomic? No. The term is not regulated. Check the adjustment list and the ranges.

How do I choose an ergonomic chair? Compare seat height and depth ranges with your measurements, check lumbar and arm adjustment, and choose a load rating with headroom.

Do ergonomic chairs need setting up? Yes. Out of the box, a chair is set for nobody in particular.