• Height of the seat from the ground, both at maximum and minimum: this affects whether your legs will inevitably dangle from the floor or whether they’ll be too close to the ground.
• The height of the headrest, and whether its adjustable
• The spaciousness and width of the seat—you don’t want to be confined
• The depth of the seat, so your back is against the back of the seat
• The amount of weight the chair can hold or is recommended to hold. Technically this isn’t chair size, but it’s close enough.

Now, in case you’re feeling overwhelmed from that, don’t worry:

If you’ve got about an average size yourself, in terms of height and weight, you will probably not have any size issues with most ergonomic chairs.

A seat width of 17-20” is standard, and should be fine for most people. A standard seat depth would leave 2-4” between the back of your knees and the seat.

If you’re taller, heavier, or even shorter than average, then you should pay more attention to the dimensions of the ergonomic office chair. Though usually it’s taller people who have issues with chairs being too small, than visa versa.

On the other hand, however, keep in mind what I said when you look at customer reviews on the ergonomic office chair you like.

For example—consider this review from a dissatisfied customer, who bought the SIHOO ergonomic office chair:

That sounds like a fair complaint, right?

Here’s the thing:

The product description, and the manufacturer, clearly state that the recommended height is below 6’3”. And the guy’s review is recent enough that it’s unlikely they only updated the description recently.

So it’s important to always read the dimensions and sizing carefully—you may even want to contact the manufacturer directly if product descriptions and reviews are not clear enough.

As a last resort, take note of the chair’s dimensions and overall shape, and compare it to similar chairs that do have recommended heights (and weights). You can even measure or dig up your existing chair’s measurements for a handy reference.

While it’s easy to get carried away looking at all the things you can adjust in your ideal chair, don’t forget to ask yourself an important question first:

Do you really want those adjustments?

This is important because they often mean the chair will be more expensive. And one can be very happy with a chair that can’t be adjusted much as long as the chair itself is comfortable and well-designed.

That being said, adjustments are useful, not just for fun, but for practicality:

It can help your workflow and if you have back, leg, or shoulder pains or stresses, then being able to adjust your seating is a life saver. Especially as everyone’s body is different, adjustments let you ensure the chair works for you.

Then, however, you need to consider what you want to be adjustable. Some people want everything to be adjustable.

But many may not care too much about the armrests, for example. The “essentials” for most people would be the basics (like seat height) but also headrests and recline angles.

If you are specifically looking for a chair because you have back pains or injuries, it would be good to not just get any old chair with lumbar support, but one with adjustable lumbar support.

Or if you just really are prioritizing posture/health with your chair purchase, lumbar adjustments are also great.

Some more on that topic:

This is one of the most important aspects of an ergonomic office chair, since it’s sort of the point of an ergonomic office chair in the first place. But it’s also one of the hardest to assess online.

However, it’s not impossible.

First, your instinctive/common sense approach will be helpful: looking at reviews. If a ton of reviews say the lumbar support is bad, that’s probably a bad sign that makes a purchase riskier.

If you only see relatively few complaints, they may be one-offs. The fact is no chair is perfect for everyone and many people have unique physical problems, so even the best ergonomic office chair can still get a bad review.

Now aside from just gauging reviews, you can assess things somewhat by looking at the product specifications themselves:

Do they look like a spine? Specifically, do they fit the curve of the lower back?

It sounds laughably simple, but you’d be surprised how useful it is to screen this way: some bad ergonomic chairs look wrong when you examine more closely.

And as stated, if adjustments for lumbar support are an option, that can be great. While it depends on the specific product, this would allow you to tweak the most important part of the chair in a way that’s good for your back, rather than being forced to rely on the default position.

After the points raised thus far, most of the rest is stuff you can figure out for yourself. Is the seat cushion thick? Does the seat’s back look comfortable, breathable?

One thing to look out for is the armrests. This is an easy point to forget, but sometimes armrests that seem appealing aren’t as good in practice.

The best way to figure out whether the ergonomic office chair you want has good armrests is to pay attention to how you work at your desk, plus what’s healthy.

If you’re among the majority of people who are going to be working on a computer while they sit in their economic office chair, then your arms will likely be pointed inwards at the keyboard, with the elbows jutting out in opposite directions.

As you can expect, if the armrests are adjustable, that can go a long way to improving armrest positioning. It’s still good to keep an eye on shape, however, as that tends to be more fixed.

Many would also want to keep an eye on the wheels. If you don’t work alone, or you’re just sensitive to noise in general, you’ll want to avoid wheels that squeak or roll loudly.