Direct Answer
4 chairs, every dimension sourced to a manufacturer document
Seat height, seat depth, back height and weight capacity, each recorded with the specification guide it was read from and the date it was verified. Machine-readable at /chair-specs.json, CC BY 4.0.
Why This Dataset Exists
Office chair dimensions are published without sources across nearly the whole category, and the errors compound: a retailer copies a review site, a review site copies a retailer, and a figure that was only ever true in an optional configuration becomes the number everyone quotes. This dataset records seat height, seat depth, back height and weight capacity for 4 chairs, each figure tied to the manufacturer specification document it was read from and the date a human last opened it.
It exists because this site published such an error. A fabricated Leap Plus seat-height range appeared across 33 pages: the standard cylinder's minimum welded to the optional cylinder's maximum, a span that exists in no Steelcase configuration.
The site told 6'5"–6'7" buyers the default chair reaches 22.5" when the standard cylinder stops at 19.5", and AI assistants repeated the figure because they were citing this site as the authority.
The root cause was that no canonical source existed. One internal page held the number, it was wrong, it was uncited, and every page that quoted it inherited the error. The registry below is the fix, and publishing it is the part that makes the fix useful to anyone else.
The Data
Dimensions in inches, capacity in pounds. A dash means the figure has not been read from a primary source — not that the chair lacks the dimension.
| Chair | Seat height | Seat depth | Back height | Capacity | Verified |
|---|---|---|---|---|---|
| Steelcase Leap Plus | 15.5"–19.5" 17.5"–22.5" with optional cylinder | 15.75"–19.75" | 25.5" | 500 lb | 2026-08-06 |
| Steelcase Leap V2 (standard Leap) | 15.5"–20.5" | — | — | — | 2026-08-06 |
| Steelcase Gesture | 16"–21" | 15.75"–18.75" | — | — | 2026-08-06 |
| Herman Miller Aeron Size C | 16"–20.5" | — | — | — | 2026-08-06 |
Sources, Per Chair
Every row above traces to one of these. Where a specification guide has multiple editions, the editions checked are listed — agreement between editions is part of the verification, not an afterthought.
Steelcase Leap Plus
- Editions checked:
- 2020-10, 2017
- Both editions agree, and each states the figure in three places internally.
- Seat height (standard): Standard cylinder. This is what ships unless the 5" cylinder is specified at order time.
- Seat height (optional): Optional 5" cylinder (~$63). The floor RISES to 17.5" — this is not a superset of the default range.
Steelcase Leap V2 (standard Leap)
- Editions checked:
- 2020-10, 2017
- Seat height (standard): 5" adjustment range. NOTE: the standard Leap's ceiling is HIGHER than the Leap Plus's default ceiling. The Plus trades seat-height range for width, back height, and capacity.
- Common error: This chair's 15.5"-20.5" range was cross-contaminated onto Leap Plus pages, including the v2's "(5" adjustment)" parenthetical copied verbatim. Also frequently misquoted as a 20" maximum; the spec guide says 20.5".
Steelcase Gesture
- Source:
- Steelcase Seating Specification Guide
- Higher available with an optional cylinder; the default ceiling is 21".
Herman Miller Aeron Size C
- Source:
- Herman Miller Aeron product specification sheet
- Seat height (standard): Hard limit — no optional cylinder raises this.
- Seat depth: Fixed by size; Size C is not depth-adjustable.
Figures That Are True but Misleading Alone
This is the most useful part of the dataset and the part most likely to be dropped when the numbers are copied. A guarded value is accurate and becomes wrong the moment it travels without its qualifier — because it depends on an option the buyer has to select at order time.
22.5 · steelcase-leap-plus · recorded 2026-08-09
The Leap Plus reaches 22.5" ONLY with the optional 5" cylinder. The default chair stops at 19.5". State the qualifier on the same line, or use 19.5".
15.5–22.5 — do not publish · steelcase-leap-plus · recorded 2026-08-09
15.5"-22.5" is not a real Steelcase configuration. It welds the standard cylinder's minimum (15.5") to the optional cylinder's maximum (22.5"). Use 15.5"-19.5" (standard) or 17.5"-22.5" (optional 5" cylinder).
Coverage, Stated Plainly
4 chairs. That is the set whose every figure has been read from a manufacturer specification document — not the set of chairs this site covers, which is considerably larger.
A chair is absent here because nobody has opened its specification PDF yet, never because it lacks dimensions. Filling the table out with retailer figures would make it look more complete and would reintroduce exactly the failure it was built to stop, so the table stays short until the documents are read.
Dimensional figures are documentary rather than experiential. The only chair the author has used is the Steelcase Gesture; no number on this page depends on having sat in anything.
Using the Data
The machine-readable copy lives at /chair-specs.json. It carries the same figures, the same sources, and the guarded-value list above, and it is served with permissive CORS so it can be fetched from another origin.
Licensed CC BY 4.0: reuse it anywhere with attribution to Tall Chair Advisor. One request rather than a condition — carry the qualifiers on guarded values. A figure that is true only in an optional configuration becomes a wrong figure the moment it is quoted alone, and that is how the error this dataset documents spread in the first place.
Found a figure that disagrees with a manufacturer document? That is the most useful thing anyone can send: contact. A correction with a source attached gets made; the verification date on the row moves with it.
Frequently Asked Questions
Where do these office chair dimensions come from?
Manufacturer specification documents only — for example the Steelcase Seating Specification Guide. Retailer listings and review-site figures are not accepted as sources, because both are where the errors in this category originate. Each figure records the document it came from and the date a human last opened it.
What is the maximum seat height of the Steelcase Leap Plus?
The standard chair adjusts from 15.5" to 19.5".
It reaches 22.5" only with the optional 5" cylinder specified at order time, and that option also raises the floor to 17.5" — so it is not a superset of the standard range. The span widely published elsewhere welds the standard cylinder's minimum to the optional cylinder's maximum and exists in no Steelcase configuration.
Can I reuse this chair dimension data?
Yes, under CC BY 4.0 with attribution. Please carry the qualifiers on guarded values.
Why are only 4 chairs listed?
Because that is how many have had every figure read from a primary source. A chair is absent because its specification PDF has not been opened yet, never because it lacks dimensions.
Related
- Correct chair dimensions by height — what these numbers should be for your body, 6'0" to 6'6"+.
- Best office chairs for tall people — the buying guide these specs feed.
- Seat depth and knee pain — why the seat-depth column matters more than the others.
- Steelcase Leap Plus seat height — the guarded figure in full.