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.

Aeron size chart

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

1. 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.
2. 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.
3. 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.

Frequently asked questions

Independent repair specialists, not affiliated with or endorsed by Herman Miller. Size ranges are guidance; individual fit varies.