Herman Miller Aeron Size Guide: A, B or C?
The wrong size is the most common Aeron mistake, and the easiest to avoid. Here's how to get it right first time.
The Aeron comes in three sizes: A, B and C. Size changes the seat width and depth and the height and width of the backrest, not just how tall the chair is. A chair that's too small leaves your thighs unsupported. One that's too large pushes the seat edge into the back of your knees. The ranges below are Herman Miller's own guidance, and they're the same for the Classic and Remastered Aeron. Height is where most people start, but waist width and weight decide whether the seat and arms actually fit your build.
Choosing by height alone is the most common Aeron sizing mistake. Waist width matters as much as height, and the height charts do not capture it.
The mistake most buyers make: sizing by height alone
Most sizing advice is built around height bands, and height is the only number most buyers check. It is one part of the picture. We size people up in person every week, and the two things the charts underweight are waist width and weight.
The Aeron's seat pan and armrest spacing are fixed for each size. If the seat edge presses your thighs or the armrests pinch in at your sides, the chair is too small for your build no matter what the height chart says. A tall, slim runner is often comfortable in a Size B. A shorter, broader rugby build is usually better off in a Size C.
So before you decide, weigh up all three: height, weight and waist width. If two of the three point at the larger size, choose the larger size.
We will size you up for free
Send us your height, weight and a rough sense of your build by WhatsApp or email and we will tell you which size suits you, free of charge, whether you buy a chair from us or not. It takes us a minute and it saves you buying the wrong chair.
Aeron size chart
| Size | Best for height | Feet & inches | Who it suits |
|---|---|---|---|
| A (Small) | 147–163 cm | 4'10"–5'4" | Petite users |
| B (Medium) | 157–183 cm | 5'2"–6'0" | Most people. The most common size. |
| C (Large) | 178–198 cm | 5'10"–6'6" | Taller or broader users |
Height ranges from Herman Miller's Aeron sizing guidance. Build matters too: if you're at the top of a range and broad-shouldered or heavier-set, the larger size can feel better. If in doubt, ask us.
Between two sizes? Choose B
Herman Miller recommends Size B for anyone whose height falls in an overlap: between 5'2" and 5'4" (A/B), or between 5'10" and 6'0" (B/C). Size B is designed to fit the broadest range of people.
How to check the size of an Aeron you already own
- Check the label under the seat. Tip the chair and look at the underside of the seat pan. The label shows the model details, including the size (A, B or C), plus the manufacture date.
- Check the date to see which generation you have. Chairs made from 2017 onwards are the Remastered Aeron; earlier chairs are the Classic. Sizing is the same for both.
- Label missing or faded? Send us a photo of the chair from the side and the underside of the seat, and we'll identify the size for you.
Does size affect which parts fit?
Some parts are size-specific and some aren't. Our extended Aeron gas lift is made for sizes B and C. Castors fit every size. Armpads are specific to Classic or Remastered, not to size. You can see our Aeron parts in the shop.
Not sure of your size? Ask before you buy.
Email us your height, and a photo of any Aeron label you have, at info@londonchairrepairs.co.uk. We'll confirm the right size before you spend anything. It's free, and it's much easier than a return.
Frequently asked questions
Already own an Aeron that needs attention? We repair Herman Miller chairs across London. See our Aeron repairs page.
Aeron chair repairIndependent repair specialists, not affiliated with or endorsed by Herman Miller. Size ranges are guidance; individual fit varies.
Choosing between models? Read our Aeron vs Embody guide.