How to Pick an Office Chair | Fits Your Body, Not the Label

A good office chair is one you can adjust to fit your own body, not one that simply carries an “ergonomic” label.

Picking an office chair comes down to one idea: the chair must fit you, not some average person. Marketing labels like “ergonomic” mean little if the chair’s fixed dimensions don’t match your frame. The practical rule for US shoppers is to prioritize seat height, seat depth, back support, and armrest adjustability over branding. If you can’t adjust those four things, the chair probably won’t support you through a full workday.

This guide covers the dimensions that matter, the minimum features to look for, and the order to adjust everything once the chair arrives.

What Body Position Should a Good Chair Support?

A properly fitted chair lets you sit with your feet flat on the floor and your thighs roughly parallel to it. Western University’s ergonomics guidance describes the ideal setup: about 2–3 finger widths should fit between the front edge of the seat and the back of your knee, with lumbar support resting in the small of your back. Your armrests should sit at resting elbow height without forcing your shoulders to hike up.

In short, you want neutral posture with room to move. A chair that locks you into one rigid position is nearly as bad as one that gives no support at all. The best chairs allow slight recline and movement so your body isn’t stuck in a single static pose.

The Key Dimensions: What to Measure on a Chair

Real ergonomic fit depends on specific measurements. Before you buy, check the chair’s spec sheet against the following targets, which Western University bases on CSA guidance.

If you’re shopping on a budget, you’ll find the best value in chairs that nail this core set of adjustments, even if they lack extra bells. Our tested roundup of bargain office chairs that still adjust properly can point you toward models that won’t wreck your posture or your wallet.

What Are the Minimum Features for a Decent Chair?

At a bare minimum, look for six things on any chair you consider:

• A seat pan that adjusts up and down
• Seat-depth adjustment so the edge doesn’t press behind your knees
• A backrest with both height and lumbar support adjustment
• Armrests that raise and lower to your elbow height
• A rounded front edge on the seat cushion
• A five-caster base for stability

The Canadian Centre for Occupational Health and Safety (CCOHS) adds that the intended user should test the chair in a real work setup before final selection. That’s the single most practical buying rule: sit in it, at a desk, for at least 15 minutes, not just for a quick bounce in an aisle.

How to Adjust a New Chair Properly

Once your chair arrives, adjust it in a specific order rather than fiddling randomly. Start with seat height — set it so the seat is just below your kneecap with feet flat on the floor. Then set seat depth so 2–3 fingers fit behind your knees. Next, move the lumbar support into the curve of your lower back, then set armrests to resting elbow height. Finally, adjust the backrest angle to something between 93 and 113 degrees of recline.

The University of Guelph suggests checking your chair’s manual for the exact lever locations, since they vary by model. If your chair has a rocking or tension adjustment, set it loose enough to move but firm enough to hold your posture.

One common mistake: armrests that sit too low or interfere with keyboard access. Western University flags this as a frequent issue. If your armrests sit lower than your keyboard, raise the chair and add a footrest so your forearms stay level.

FAQs

Is a more expensive chair always more ergonomic?

No. The Ontario government’s occupational health guidance (OHCOW) notes a chair is only ergonomic if you can adjust it to your own dimensions. A cheap chair with full adjustability often beats a pricey fixed-frame model. What you’re paying for in higher-end chairs is usually material quality, durability, and a wider adjustment range rather than automatic fit.

Can I make a non-adjustable chair work with add-ons?

Only partially. A lumbar cushion or a footrest can help, but they can’t fix a seat pan that’s too deep or armrests that force your shoulders up. If the chair’s core dimensions don’t fit, accessories are a temporary patch, not a solution. Your best move is to find a chair with real adjustments, even if it means spending a bit more.

Should I buy a chair online without sitting in it first?

Only if the return policy is generous and the spec sheet shows the adjustments listed above. CCOHS advises testing a chair in a real work scenario, and a 15-minute showroom sit is better than guessing. If you buy online, check that the retailer covers return shipping, since you may need to exchange the seat depth or height.