Herman Miller Aeron or Cosm: Which Is Better?

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Thinking about pulling the trigger on an ergonomic chair, and tossing up between the Herman Miller Aeron and Cosm chairs? 

Each chair is an icon within the Herman Miller range, and has its own strengths and weaknesses.

In this article, we’ll discuss how these chairs stack up based on key factors. This includes price, ergonomic features, appearance, build quality and suitability for impressing members of the opposite sex. 

Key “high level” comparisons are provided in tables where relevant, with more detailed information following.

You’ll leave with a more informed picture of each chair and which one may suit you best. If you’re still on the fence, you can also check out some of our favorite Aeron alternatives.

Herman Miller Aeron vs Cosm v2 Quick Comparison

Herman Miller Aeron chair

The Aeron is the flagship high-end chair by Herman Miller, with over 8 million sold. It is widely recognised for its top-tier build quality, distinctive Pellicle mesh fabric and adjustability. With a smooth recline, the chair is meant to feel like you’re “floating on air”.


  • Supports three different sizes
  • Top tier build quality 
  • Highly adjustable overall
  • Very smooth recline function 
  • Breathable and comfortable mesh
  • Comfortable armrests
  • Good warranty & return policy
  • Ships fully assembled
  • Large market for used Aerons, giving more options to acquire cheaply or to resell in the future 


  • Seat edges are hard and curved upwards, which some find uncomfortable
  • No seat depth adjustment 
  • No back height adjustment
  • No armrest width adjustment 
  • Frame from the seat and back can be felt by some users
  • Limited options in terms of appearance & color
  • Slightly more expensive than the Cosm

Herman Miller Cosm chair

Making Time magazine’s list of “100 Best Inventions”, the Herman Miller Cosm chair is a newer addition to the Herman Miller ergonomic line up. Sporting a minimalistic, sleek design, the chair adapts flexibly to your body type and movement. 

It does this via a special design feature called “Auto-Harmonic Tilt”, which senses your body weight and dynamically adjusts the tension to provide optimal support.


  • Adjusts automatically to your body (no complicated adjustment knobs)
  • More comfortable seat edges than the hard seat edges of the Herman Miller Aeron
  • Sleek, beautiful design
  • Highly flexible frame 
  • More color options than the Aeron
  • Good warranty & return policy
  • Ships fully assembled


  • Leaf arms option can be uncomfortable for some users
  • Less control over adjustments than the Herman Miller Aeron
  • Only one overall chair size (but the backrest comes in low-back, mid-back and high-back varieties)
  • Lumbar support is not directly adjustable
  • Hard to maintain fully upright posture due to slight natural recline

With that quick comparison of PROs and CONs out of the way, let’s walk through a more detailed comparison of chair features.

Herman Miller Aeron vs Cosm: Price

Price quick comparison table

How much you pay for the Herman Miller Aeron chair or the Herman Miller Cosm chair depends on which optional add-ons you select.  

See the table below for a rough idea of the price range, based on your choice of add-ons (in USD).

Most basicWhat most will wantMaximum add-ons
Herman Miller Aeron$1195
Starting price
“Bare bones” features
Adjustable armrests & lumbar support
Tilt limiting & seat angle
“All of the options please”

Herman Miller Cosm$895
No headrest (low-back backrest)
Fixed armrests
Graphite frame
Wheels for carpet only
No headrest (mid-back backrest)
Height adjustable armrests
Graphite frame
Wheels for carpet
Headrest (high-back backrest)
Leaf armrests
More premium frame
Wheels for hard floor and carpets

Typically, the Herman Miller Cosm chair will cost around $300 dollars less than the Herman Miller Aeron chair.

Of course, the price difference depends on the add-ons selected for each chair, but that gives you a general idea.

Also note the middle column in the table above is subjective based on what I would personally expect in a top-end chair. 

I encourage you to check out the Cosm product listing page on the Herman Miller website, as well as the official Aeron listing. You can test different add-ons to get an exact price for what you care about.

Herman Miller Aeron price 

The Herman Miller Aeron chair ranges from $1195 (starting price) – $2195 (maximum price with add ons) [1].

The starting price is the “no frills” option, with no adjustable lumbar support, no tilt limiter or seat angle adjustment, stationary armrests and graphite frame . 

As I’ve observed in a previous article, for the “over $1,000” price range, I’d expect to have these features. In my view, not having them defeats the point of this kind of chair.

Therefore, arguably, you’re looking at closer to $1625 for an Aeron chair with a decent level of adjustability. At that price point, you’ll get fully adjustable armrests, adjustable lumbar support and tilt limiting / seat angle capabilities. 

To see the various customisation options and their cost, check out the Aeron product page.

If this price range is out of your budget, you can always consider a used Aeron chair. This is a more budget-friendly way to get your hands on one of these bad boys.

Herman Miller Cosm price

The Herman Miller Cosm chair ranges from $895 (starting price) – $1995 (maximum price with add ons) [1].

Again, if you want some basic adjustability, expect to pay closer to $1295. This will get you the mid-back Cosm with height-adjustable armrests.

You can explore the different add-ons and associated price impacts on the Cosm product listing page.

Herman Miller Aeron vs Cosm: Ergonomic features

Feature comparison table

Herman Miller AeronHerman Miller Cosm
AdjustmentsManual knobs & leversAutomatic
Sizing3 sizes1 size only, but three backrest heights 
SeatHeight adjustable
Seat angle adjustable
Hard “curved up” seat edge
Height adjustable only
No upwards curves on seat edge
Lumbar SupportHeight adjustable lumbar pad OR tension-adjustable PostureFit supportDynamic, flexible support 
Not manually adjustable
ArmrestsHeight adjustable
Depth adjustable
Pivot adjustable (in, straight or out)
Height adjustable OR fixed
No depth, width or pivot adjustment
TiltDynamic seat tilt
Tilt tension adjustable
Tilt limiter & lock
Forward tilt
Automatic tilt 
No tilt locking or limiting


The Herman Miller Aeron chair comes in three sizes. These are Size A (small), Size B (medium), and Size C (large). 

This allows you to pick a chair size that works best for your body.

Most people find the Size B Aeron chair works best for them. So that may ‘B’ a good starting point! However, smaller uses will want Size A and larger users will want Size C. You’ll have to ‘C’ what works for you! 

*crickets chirping*… I’ll see myself out.

For more information on how to find the right Aeron size, check out our article here.

By contrast, the Herman Miller Cosm chair only comes in one “frame” size. That said, you can choose between low-back, mid-back and high-back varieties. 

While the chair dimensions in terms of width and depth are virtually the same across all three types, the backrest height is different for each type. 

This allows you to pick the right level of back support for your particular body type and preferences.

See the table below for a height comparison:

Low-back40.25 inches (102.2 cm)
Mid-back45 inches (114.3 cm)
High-back51.25 inches (130.175 cm)


You can adjust the seat height in both the Herman Miller Aeron and Herman Miller Cosm chairs.

This is done via a pneumatic seat height level adjustment.

In the Aeron, the seat angle can also change as part of the tilt function, but this angle isn’t directly adjustable.

You cannot adjust seat depth in either the Aeron or the Cosm chairs. Seat depth is how far forward or back the seat is relative to the backrest.

To ensure a comfortable distance from the back of your knees, changing the seat depth helps. Therefore, it’s a shame this isn’t an option for these chairs.

In the Aeron’s case, this is less of an issue due to the multiple size options, which ensures the default seat depth will typically work.

The lack of seat depth adjustment is more of a problem for the Cosm chair, which only comes in one size. Users that are small or have shorter legs may find the default seat depth in the Cosm uncomfortable.

One aspect of the Cosm seat that some like is the lack of hard, upturned edges.

Instead, the seat edge in the Cosm is flat on the sides and curved downward at the front, sporting a gentle waterfall design.

Some find this more comfortable than the Aeron seat edges, which are harder and curved upwards. 

Sitting on the Aeron feels more like sitting “in” the chair, with the edges of the seat “hugging your backside”. 

By contrast, sitting in the Cosm feels more like you’re sitting “on” the chair.

Lumbar support

The Herman Miller Aeron chair and the Herman Miller Cosm chair take a different approach to lower back or lumbar support.

The main difference is that in the Aeron, you’ve got the option of adjustable lumbar support. 

This can be a simple height-adjustable lumbar pad, which you can move up or down. You can also turn the lumbar pad around to slightly increase the lumbar pressure applied. 

The Aeron alternatively offers a larger “PostureFit” support, which consists of two separate pads supporting both the sacral (tailbone) and the lumbar (lower back) regions. 

The PostureFit support can’t be moved up or down, but you can adjust the forward pressure.

To see these two lumbar support options in action, check out this video:

In the Cosm, your lower (and entire) back is supported by a springy mesh backrest, which is shaped to fit the contours of your lower back. The mesh conforms to various body shapes and offers “dynamic spinal support”.

In other words, the Cosm doesn’t provide the option of manually adjusting the position of the lumbar support. Instead, it relies on this springy mesh to automatically provide appropriate support.

Some users like the idea of a chair that tries to automatically do this. However, many others prefer having more direct control over the position and pressure of their lumbar support.

Personally, I count myself in the latter category, but this comes down to personal preference. 


The Herman Miller Aeron armrests have more adjustment options available then the Cosm armrests.

In the Aeron, your armrest options are: height-only adjustable armrests, fully adjustable armrests, or fixed armrests. 

The fully adjustable armrests means they are height adjustable, depth adjustable (forward or back), and pivot adjustable (angled inwards, straight or outwards). Note: one small limitation is they are not depth adjustable like some other ergonomic chairs (i.e. the Steelcase Leap).

The Herman Miller Aeron armrests are attached to the backrest, so change angles with you as you recline. This provides improved arm support. 

The Aeron armrests are known for being highly comfortable and soft to the touch, and are finished in either soft polyurethane foam (standard armrests) or leather for an extra fee.

In the Herman Miller Cosm chair, there are three armrest options.

These are: 

  1. Height-adjustable armrests
  2. “Leaf” armrests; or
  3. Fixed armrests

The height-adjustable armrests resemble the style you often find in other ergonomic chairs. They come with soft, opaque padding and can be moved up or down.

For $100 extra, you can opt for the Leaf armrests instead. The Leaf armrests are made of the same breathable mesh fabric you find on other parts of the chair. 

Instead of being parallel to the ground like the other options, they’re angled downwards (almost at a 45 angle). They look a bit like hammocks for your arms.

You can see an example of the Leaf armrests in this YouTube review:

Some users find the mesh in the Leaf armrests uncomfortable against their skin. The lack of adjustability here is also a real con, especially given you’re paying extra.

Finally, you can opt for the basic fixed armrests made from solid material. This is the cheapest “barebones” option (cheaper than the Leaf armrests by $200). 

In my view, if you’re already committing to a high-end chair like the Cosm, it doesn’t make much sense to skrimp on your armrests. Of course, this is a personal preference thing and it’s your call. 


The tilt or recline function works differently in the Cosm chair compared to the Aeron chair.

The primary difference is that in the Herman Miller Cosm, the tilt functionality is fully automatic.  

A special system called ‘Auto-Harmonic Tilt’ tries to provide a dynamic amount of resistance based on your weight and body movements.

In the Herman Miller Aeron, tilt functionality can be more directly controlled via manual adjustments.

The first thing that can be controlled is the tilt tension, which is the amount of forward resistance provided by the chair. This can be adjusted by a dial on the side of the chair.

The other thing that can be controlled is tilt limiting, which is a feature that lets you limit how far back your Aeron chair can recline. You can do this via the tilt limiter add-on, which comes as a dial on the other side of the chair. 

If you’ve got a modern Herman Miller Aeron Remastered chair, there are three available tilt limit positions. These are: a fully reclined position, a medium level of recline, and a fully upright position.

If you’ve got an older Aeron Classic model (pre-2017), you’ll be able to set the tilt limit position at any point in the recline range. So, surprisingly, the older model has greater adjustability in this regard.

As well, the Aeron also supports a forward tilt feature as part of the tilt limiter add-on. This allows you to tilt the backrest and seat angle forward, which some users like when they want to adjust their pelvic tilt or focus on a task. 

As mentioned, the Cosm chair provides no way to lock the tilt or change the tilt tension directly. 

Some users like not fiddling with adjustment knobs and instead relying on built-in smarts to provide appropriate recline support.

However, many others prefer controlling how their chair behaves more directly. So keep this difference in mind when considering each chair.

Herman Miller Aeron vs Cosm: Appearance

In terms of aesthetics, one key difference between the Herman Miller Aeron and Cosm chairs is the color options.

The Herman Miller Aeron chair only offers a selection of neutral colors, ranging from black or dark grey (graphite) to silver (mineral / aluminum).

You can see what each color option on the Aeron looks like here.

The Herman Miller Cosm chair also offers a range of more muted grays, browns and whites. However, if you’d like more personality, you can also opt for a deep red color (“Canyon”).

You can see what each color option on the Cosm frame looks like here.

In terms of overall look, the Aeron has an elegant but more traditional appearance.

The Cosm looks more like it belongs on a designer’s instagram page. It has a stylish curved frame, with a distinctive flexible back support.

Which look you prefer comes down to your personal taste. Both chairs are a stylish addition to most office setups.

Herman Miller Aeron vs Cosm: Build materials & quality

Both the Aeron and Cosm are built with high-quality components.

Berlin-based designers Studio 7.5 spent several years perfecting the design and build materials in the Cosm.

Built with light materials and a minimalistic design, the Cosm chair weighs around 35 lbs. 

The frame based and armrests are made from polyamide (nylon) and polypropylene (A.K.A. the “steel of plastics”) materials. This combination makes it highly durable, moisture-resistant and heat-resistant.

The Aeron chair uses plastic (especially the newer Remastered model) and aluminum in its construction. 

The build quality and finish on the Herman Miller Aeron chair is something of a gold standard in the ergonomic chair market. So on this front both chairs are solid picks.

One difference with the overall appearance of the Aeron is the adjustment knobs and levers. This gives the chair a less minimalistic feel, since you’ve got more going on compared to the Cosm. 

That said, these adjustment mechanisms are not over-the-top and the overall design is still sleek.

In terms of upholstery, both chairs heavily use a breathable mesh fabric across both the seat and backrest.

The Cosm chair calls this “elastomeric intercept suspension” mesh. It is breathable, temperature-neutral and designed to give you a feeling of weightlessness.

The Aeron chair uses an 8Z Pellicle mesh. This material allows heat to pass through the seat and backrest. It also provides eight zones of varying tension (hence the “8Z”) to promote circulation. 

If you’re on the heavier side, either chair should have you covered. Both the Aeron and the Cosm can support up to 350 lbs

Warranty & returns

Both the Herman Miller Aeron and Cosm chairs are covered under Herman Miller’s 12 year warranty, which covers both parts and labor.

If replacement parts need to be sent or repairs need to be made, Herman Miller will cover the cost. This may involve Herman Miller sending the parts to you free of charge, or a Herman Miller technician providing repairs. 

So both chairs offer a solid (and equal) warranty. This gives you confidence they’ll have a long shelf life.

Herman Miller Aeron: Suitability for impressing members of the opposite sex

You can’t spell ‘Aeron’ without an ‘A’. Similarly, you can’t spell ‘Aphrodisiac’ without an ‘A’. 

If that’s not a sign, I don’t know what is.

Rating for suitability to impress: 7.5/10.

Herman Miller Cosm: Suitability for impressing members of the opposite sex

With a sleek, modern look, nothing screams “I’m worth dating” like owning a Herman Miller Cosm chair.

Rating for suitability to impress: 8/10.

Verdict: Is the Herman Miller Aeron or Cosm better?

Both the Herman Miller Aeron and Cosm chairs have loyal fan bases.

If you like the idea of a chair that automatically adjusts to your body, the Cosm may be a great option. You’ll be able to use your chair without the friction of manually adjusting various knobs and levers.

The Cosm may also suit you if you dig the minimalistic and sleek look, or want the option of a red frame.

Although not cheap, the Cosm still comes in at (typically) $300 or so less than the Aeron. So if you’re undecided, that’s a factor to consider as well.

On the other hand, if you value having more control over chair adjustments, the Aeron will likely be a better pick.

The Aeron also has a distinctive “dignified” look that you may prefer, depending on your taste and on what fits your workspace.

I’d recommend you look for any Herman Miller and Steelcase showrooms near you before committing to either chair.

That way, you can try each chair in person to see how each feels for your particular body. 

Thanks for reading. I hope this article has helped you understand how the Cosm and Aeron compare.


[1] https://store.hermanmiller.com/office-chairs-ergonomic-chairs?lang=en_US