Guide · 2026-08-01
Herman Miller Aeron Size Guide (A vs B vs C)
Bottom line
Aeron uses three sizes. Remastered product literature rates Size A to 300 lb, Size B to 350 lb, and Size C to 400 lb, with seat depths roughly 16.4", 17", and 18.9". Height guidance across Remastered sizes is about 4'8"–6'7". When in doubt between B and C, prioritize seat depth and hip width over height alone.
Why does the Aeron come in three sizes?
Aeron is sized because Herman Miller changes the frame geometry across A, B, and C—not just the gas cylinder sticker. Seat depth, seat width, and back envelope all shift with size, so a tall person in a shallow Size B can still feel undersized even when the height range looks fine on paper. Remastered product literature rates Size A to 300 lb (~16.4" seat depth), Size B to 350 lb (~17"), and Size C to 400 lb (~18.9"), with overall height guidance about 4'8"–6'7" across the family. Treat those numbers as starting constraints: capacity tells you the warranty story, while depth and hip width tell you whether the pan actually fits. If you are between B and C, choose the size that keeps your hips fully supported without hard front-edge pressure rather than chasing height alone.
Classic vs Remastered Aeron: which generation should I buy?
Buy Remastered when you can: it is the post-2016 generation with 8Z Pellicle, PostureFit SL, Harmonic 2 tilt, and the expanded per-size capacity story most shoppers expect today. Classic Aerons (pre-2016) remain common on the used market and can be excellent value, but they generally topped out around 300 lb with a narrower height story and older lumbar/tilt hardware. Listings often say only “Aeron,” so verify generation from photos of the lumbar design, tilt mechanism, and underside labels before you pay Remastered prices for a Classic frame. Size is still structural on both generations—you cannot convert B to C—so confirm A/B/C on the frame itself. If the seller cannot identify size and generation clearly, treat the deal as incomplete until they can.
How do I check Aeron fit before I buy?
Start with seat depth and hip width, then confirm cylinder height against your desk. Sit so your hips fill the pan without hanging off the front edge or compressing into hard side boundaries; if your thighs overhang a Size B, try C before you blame the mesh. Feet should plant firmly—if they cannot even on a low cylinder, fix desk height or reconsider size rather than forcing a taller frame. Remastered Size B is the most common reference config on ChairAtlas (350 lb), but Size C is the usual path when you need more depth or the 400 lb rating. Headrests are aftermarket-only on typical Aerons, so do not assume a factory headrest is part of the size decision. When shopping used or refurbished, match the listed size to the frame stamp and re-check wear parts (cylinder, casters, arm pads) after you lock the size.
FAQ
- Can I convert an Aeron from Size B to Size C?
- Not practically. Size is structural. Buy the correct frame.
- Should I choose Aeron size by height or by seat depth?
- Prioritize seat depth and hip width. Height range is a filter; a correctly deep pan matters more when you are between B and C.