Herman Miller Aeron Size B vs Size C: Which Size Should You Buy?
Choosing the right Herman Miller Aeron size is one of the most important decisions when buying the chair.
Unlike most office chairs, the Aeron isn't designed as a one-size-fits-all product. Herman Miller produces it in three distinct sizes — A, B and C — with differences in the seat, backrest and overall proportions of the chair.
For most Australian buyers, the decision comes down to Size B vs Size C.
The short answer:
Size B is the best choice for most people. Size C is designed for taller or larger users who benefit from a wider and deeper seat and a taller backrest.
However, height alone doesn't always determine which one will feel better. This guide explains the differences and how to choose.
Aeron Size B vs Size C at a Glance
This is the link for Herman Miller’s Aeron Size Chart: https://www.hermanmiller.com/content/dam/hermanmiller/documents/product_literature/other/aeron_chair_size_fit_ref_en-apc.pdf
Aeron Sizing Chart
Herman Miller's current sizing guidance recommends Size B for people approximately 158–183 cm tall, while Size C is recommended for approximately 178–200 cm. There is deliberately a significant overlap between the two sizes.
That overlap is where choosing becomes more personal.
What's the Difference Between Aeron Size B and Size C?
The Size C isn't simply a Size B with a higher weight capacity.
The whole chair is proportionally larger.
Compared with Size B, the Size C has:
A 40 mm deeper seat
A 28 mm wider seat pan
A 31 mm taller backrest
A slightly higher seating position
Herman Miller also changes other components between sizes, including aspects of the chair's tilt mechanism and base.
This means you can genuinely feel the difference when sitting in the two chairs.
The Size B feels more compact and supportive around an average-sized user, while the Size C provides noticeably more room through the seat and backrest.
Should Most People Buy Aeron Size B?
Yes.
If you're around average height and build, Size B is generally the safest choice.
Herman Miller itself recommends Size B for users who fall around the boundaries between its different sizes because B was designed to accommodate a particularly broad range of people.
Size B is particularly worth considering if:
You're below approximately 183 cm
You have an average or slimmer build
You don't want an excessively deep seat
You prefer a chair that feels more closely fitted around you
Multiple people of different sizes will use the same chair
For a home office or workplace where the chair may occasionally be used by different people, Size B is normally the more versatile option.
When Should You Choose Aeron Size C?
Size C starts becoming particularly attractive for taller and larger users.
Consider Size C if:
You're approximately 185 cm or taller
You have long legs
You have a broader build
Size B feels narrow through your hips or thighs
You want more seat depth
You prefer a larger backrest
The additional 40 mm of seat depth is especially noticeable.
For someone with long legs, this can provide substantially more support beneath the thighs. For someone with shorter legs, however, that same additional depth can become a disadvantage.
Seat Depth Is More Important Than You Might Think
One of the biggest mistakes when choosing an Aeron is focusing only on your height.
Seat depth matters enormously.
When you sit fully back in an office chair, there should still be some clearance between the front edge of the seat and the back of your knees.
Herman Miller recommends leaving at least a couple of fingers' worth of space between the seat edge and the back of your knee.
This is one reason why simply thinking "bigger chair = more comfortable" isn't necessarily correct.
The Aeron's mesh seat is surrounded by a rigid frame. If the seat is too deep for you, that front frame can sit too close to the back of your legs.
Size C can therefore be fantastic for someone with long legs while Size B may actually be more comfortable for someone only slightly shorter.
I'm 6'0" — Size B or C?
At around 183 cm (6'0"), you're right in the crossover area.
Both can potentially work.
For an average or slimmer build, we'd generally lean towards Size B.
If you're broader, have particularly long legs, or simply prefer a roomier chair, Size C may be preferable.
This is one of the heights where trying both sizes before purchasing can be particularly useful.
I'm 6'2" — Size B or C?
At approximately 188 cm (6'2"), we'd generally lean towards Size C.
You're well within the height range for Size C, and its additional seat depth and taller backrest are more likely to suit your proportions.
That doesn't mean a 6'2" person can't comfortably use Size B. Body proportions vary considerably.
Someone who is 6'2" with a relatively shorter leg length and slim build may still prefer the more compact B.
But if we had to choose without you trying the chairs first, Size C would generally be the better starting point.
Is Aeron Size C More Comfortable Than Size B?
Not inherently.
It's simply larger.
This is an important distinction.
Buying an Aeron Size C because you want the "better" or "more comfortable" version is a little like buying shoes a size too large because there is more room inside them.
The best Aeron is the one that fits you properly.
A correctly sized Size B should be more comfortable than an oversized Size C for an average-sized user, just as a properly sized Size C can be substantially better for a tall user who feels constrained in B.
What About Aeron Size A?
Size A is the smallest Aeron and is much less commonly considered by average-sized adult buyers.
Herman Miller recommends it for users approximately 142–163 cm tall. Its seat and backrest are both smaller than Size B.
If you're particularly petite, however, Size A shouldn't be overlooked.
One of the Aeron's greatest strengths is that Herman Miller didn't attempt to make a single chair accommodate everybody. The three-size system allows the proportions of the chair itself to change to better match the person sitting in it.
How Can You Tell What Size an Aeron Is?
There is a simple trick.
Reach underneath the upper edge of the Aeron's backrest.
You'll feel a series of raised dots:
One dot = Size A
Two dots = Size B
Three dots = Size C
This is useful when looking at an Aeron in an office or purchasing a pre-owned chair where the size isn't immediately obvious.
Can You Try an Aeron Before Buying?
If you're directly between Size B and Size C, trying them is the ideal option.
When testing the chair, don't just sit down for ten seconds and decide which feels softer.
Sit fully back in the chair and look at:
Seat depth: Is there still clearance behind your knees?
Seat width: Do you have comfortable space beside your legs without the frame pressing against you?
Backrest: Does the backrest feel appropriately proportioned to your torso?
Armrests: Can you position your arms naturally while sitting correctly?
PostureFit SL: Does the lumbar and sacral support meet your back in a comfortable position?
You should be assessing fit, rather than simply asking which chair feels bigger. If you are in Perth, Curated Office Chairs is the best place to try out an Aeron, where you can book a free obligation free appointment with them to try out Herman Miller chairs. We, Curated Office Chairs also have an Aeron available to try out in our Melbourne partner warehouse. If you are in Melbourne looking to buy an Aeron, this makes Curated Office Chairs an excellent spot for you. For people looking to buy a Herman Miller chair such as the Aeron in Sydney, Adelaide, Brisbane, Tasmania or Canberra, many of our customers go to a showroom closest to them, before ordering with Curated Office Chairs for excellent prices for Herman Miller Aerons, Sayl and Embody chairs.
Size B or Size C: Our Recommendation
Choose Size B if:
You're approximately 158–183 cm, have an average build and aren't sure which size to choose.
Choose Size C if:
You're approximately 185 cm+, have a larger build or particularly long legs, or you've tried Size B and find the seat too small.
In the overlap:
Your proportions and personal preference become more important than your height alone.
If you're deciding between the two, seat depth is probably the single most useful thing to pay attention to.
Final Thoughts
Part of what makes the Herman Miller Aeron unusual is that you're not simply adjusting one generic chair to fit you.
The chair itself comes in different proportions.
Size B covers an exceptionally broad range of users and will be the right choice for most people. Size C takes the same Aeron design and scales key dimensions up for people who need more seat depth, width and backrest height.
If you're well within one size range, the decision is generally easy.
If you're sitting in the crossover between B and C, consider your leg length, build and preferred amount of space in the chair, rather than relying purely on height.
Still unsure which Aeron size is right for you? Contact Curated Office Chairs and we're happy to help you choose between Size B and Size C before ordering.