Buying Guides

Herman Miller Aeron Size B vs C: Which Fits You?

By the Pro Furniture Team 2 min read

Published

Choosing between Aeron Size B and C? Start with the size that fits your body, rather than assuming bigger is better. Height and weight are useful starting points, but leg length and body proportions matter too.

1. Check the space behind your knees

Sit all the way back with your feet supported. As a practical guide, look for around two to three fingers of clearance between the seat edge and the backs of your knees.

If Size C presses behind your knees or makes you slide forward, try Size B. If B feels too short under your thighs, C may offer a better fit, provided you still have that knee clearance.

2. Check the room around your hips

Your hips and thighs should sit comfortably within the seat, without pressure from the firm outer frame. Size B is a good option if you feel comfortably supported in its medium seat. Size C is worth trying if B feels restrictive around your hips or thighs.

3. Check your back support

With your hips fully back, the backrest should support you naturally. Try both an upright working position and a reclined position. You should feel supported without needing to shift forward to get comfortable.

Size B or C: a practical comparison

Use fit checks alongside the manufacturer’s sizing chart.
What you notice What to try
Size C presses behind your knees Try Size B and check your seat height.
Size B feels restrictive around your hips Try Size C, then recheck knee clearance.
Both sizes feel comfortable Start with Size B and compare both in your usual working position.

Our recommendation

Herman Miller’s sizing chart recommends B for people in the B/C overlap. Treat that as a starting point for a fitting, rather than a substitute for sitting in both sizes.

Spend 10–15 minutes in each chair, adjust it and try your usual working position. If neither fits comfortably, try a different size or chair model.

Explore the Herman Miller Aeron, or book a showroom visit and ask our team about comparing B and C. Confirm the sizes available to try before travelling.

You try so you know!

Sources and further reading