Herman Miller Cosm vs Aeron: Office Chair Showdown series

Herman Miller’s Aeron is the brand’s most popular highly adjustable ergonomic chair This iconic office chair even earned a permanent spot in the Museum of Modern Arts. Yes, the Aeron is definitely an office chair to reckon with. It may be the best Herman Miller chair for most.

But through a decade of research and perfections, the Cosm chair may have its own battle to emerge as the victor, that’s the passive ergonomics. And it’s the opposite of the ideology of Aeron. Let’s see what both chairs may have in common. And let’s elaborate on the numerous differences.

Aeron office chair
Aeron office chair

The Herman Miller Cosm – New kid on the block

The Herman Miller Cosm is perhaps one of the newest innovations from the brand. It was released in 2018 and has been gaining attention since then. The Cosm chair took a decade to perfect. Some brands also produced their own version of a passive ergonomic chair, but those chairs didn’t live up to the par. Passive ergonomic chairs weren’t seen as something that you would want to use.

And the desire to create a passive ergonomic chair that could benefit users sparked the creation of the Cosm.

Herman Miller Cosm
Herman Miller Cosm

Office Chair Showdown – Herman Miller Aeron vs Cosm

Both the Aeron and the Cosm offer several configurations to make your office chair personalized. From the caster wheel, the upholstery, up to the arrest options, you can choose the one that fits your needs.

Configurations and customization

What’s notable is that the Cosm is available in three back sizes- low back, mid-back, and high back. So it provides options for the shorter sitters and the taller ones. 

This is the same with Aeron. With the iconic chair available in three sizes, A, B, and C, taller and heavier sitters can find their ideal office chair But of course, but of course, there may be an advantage in the side of the Aeron. Apart from the backseat, the weight capacity and the width of the seat also increase if you purchase the Aeron C. Whereas with the Cosm, only the seat height is variable.

Scope of users

Though the Cosm offers three sizes for the back seat, it lacks some other adjustability that can make an office chair more versatile. Lack of seat depth adjustment and lumbar support can make it seem lacking for some.

The Aeron, on the other hand, is still the most adjustable Herman Miller office chair. Asda from the three Aeron chair sizes, you have options to upgrade to more adjustable features such as a fully adjustable armrest and seat angle adjustment. And there’s also the adjustable lumbar support that everyone is raving about. 

So in terms of the scope of users, the Cosm may be a bit limited compared to the Aeron chair.

Weight capacity

The weight capacity of the Cosm is 350 lbs. So it’s quite heavy duty. And it also has the same carrying capacity as that of the Aeron C, though you just have to purchase the biggest Aeron size to get that same weight capacity. Both office chairs are also designed to be sat on 24/7.


We also love the ease of shipping. Both chairs come fully assembled. And I love how Herman Miller packages its chairs. Your purchases are fully protected but they just use lesser materials. It’s like you open the box, and the chair is ready to roll. So that’s no setup and no installation for both chairs. And everyone would love that.

I love the warranty that you can get with the Cosm chair. It offers a 30-day satisfaction guarantee. So if you’re not happy with the chair after 30 days, you can still return it to the manufacturer. And they’ll be glad to take it off your hands.

And it also has the same 12 years coverage as the Aeron chair. 

Seat comfort

The Cosm chair, with its all mesh covering, does provide good support. But it can be too firm or too stiff for some. So the chair comfort is quite subjective. And the frame at the side of the chair can get too stiff on your buttocks if you’re on it for too long. So if you’re not up for a very firm seat, this isn’t for you. 

The Aeron, on the other hand, does provide firm support for your buttocks. But it won’t get too stiff or too firm. So in terms of the comfort of the seat, many will find the Aeeron seat more comfortable. There’s no pinching sensation in the buttocks.

Backrest support

In terms of back support, the Cosm has very impressive back support. The overall shape of the backrest has a larger curve at the lumber and the top. So that makes up for the lack of lumbar support. And the high back version provides a build of a head or neck rest.

I felt supported from the lower back, mid back up to the shoulders and neck area too. The Cosm’s bottom of the back is connected to the seat, the lack of the gap provides more support for your entire body. It feels like you’re being cradled in the chair. 

The Aeron chair, on the other hand, became popular for its impressive lumbar and back support. That, I will not contest, because I’m also a fan of it! But in terms of the head or neck rest, it’s something that you’ll find missing in the Aeron. Those people who want to have their neck cradled will favor the Cosm over the Aeron.

But those with lumbar and back problems will find more comfort in the Aeron.

Construction, build, and quality

The Cosm is made of entire plastic and aluminum, so it created a lightweight chair. And the build quality is one of the best I have encountered among all office chairs that I’ve tried. It may be a bit better than the build and construction of the Aeron. 

The Cosm was designed with the build, the quality, and the aesthetics in mind. Even from the side view, you’ll notice how handsome and sleek the Cosm chair is. The entire structure or every part of the Cosm chair is well built. From the rinds to the shape of the chair, careful thought was given. And oh well, it took ten years to perfect.

It’s an all-mesh chair too. And it’s impressive how the mesh is woven together. And the overall color of the Cosm is very uniform.

The Aeron is also a well-built chair, it wouldn’t be iconic if it wasn’t. But the Cosm looked more stylish and looked like much thought was given in its creation. I think because it’s a passive ergonomic chair, so everything has to make up for what’s lacking. 


Both chairs are flexible. And the plastic back moves with you. But if I’ll be choosing one over the other, it’s the Cosm. The backrest is connected to the seat itself. The lack of a gap makes the chair more flexible. And it can really move with you. It can give you a wider range of motion when compared to the Aeron.


Cosm has three options for the armrests, the standard, the adaptable, and the butterfly arms. Among the three, the butterfly arms are the most intriguing, yet the most sought after. 

Though unadjustable, the angle of the butterfly armrests was designed in a way to provide comfort for all users. But even if it was designed so, I still find myself wanting to do some adjustments with it. Though the design and overall look make the chair look more cohesive, the mesh butterfly arms didn’t do anything for me in terms of comfort.

The butterfly arms make it easier to snug the desk under your desk without the arms getting in the way. Though the mesh material allows your elbow to sink in providing better support, the problem lies with the mesh being too abrasive on your skin. After sitting for the entire day, you can see and feel the etched mesh on your skin. And it can be very uncomfortable.

And the frame on the arms of the Cosm chair becomes more pronounced because of the softer mesh material. So that makes it feel hard on your elbow and arms.

So instead of going with the hype of the butterfly arms, it’s better to just purchase one with the standard or the adjustable arms. So in terms of the arm comfort, if you’re going to get the fully adjustable arms of the Cosm, it plays around the same game with the Aeron chair.


The Cosm chair is designed without much ergonomic adjustment. It only has a seat height adjustment and a tilt. The tilt is very comfortable and has a natural rocking motion. The chair will definitely tilt you back, so expect to be in a slightly reclined mode all the time.

The Aeron, on the other hand, is fully adjustable, there is no doubt about that. That made it one of the most sought after chairs of all time.

compare the price

Final word

The Cosm chair isn’t made for everyone. With the lack of adjustments, all mesh material, it’s very user-specific. But what you’re getting is one of the best office chairs with the best build and great warranty. It’s for those who don’t want the fuss of adjusting their chair. But it can be a high-end task or conference chair. 

The Aeron, on the other hand, works for almost all people especially those who have lumbar and back problems. It’s perfect for those looking for a more adjustable ergonomic chair.