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Herman Miller Cosm (Mid Back)

Ranked #13 of 24 in Best Ergonomic Office Chairs: Herman Miller, Steelcase, Haworth & More (2026). Here is every spec we scored, where it came from, and how it compares.

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#13

Herman Miller Cosm (Mid Back)

Best for: Auto-Harmonic tilt, no tension knob

5.7/10

What we like

    Watch out for

    • Seat depth adjustment not published by Herman Miller
    • Maximum seat height not published by Herman Miller
    • Minimum seat height not published by Herman Miller
    • Armrest adjustments not published by Herman Miller

    Score breakdown

    Weight capacity 25%
    Warranty length 20%
    Seat depth adjustment * 15%
    Maximum seat height * 10%
    Minimum seat height * 10%
    Armrest adjustments * 10%
    Adjustable lumbar * 5%
    Forward tilt * 5%

    * Not published by the manufacturer; scored at the lowest published value in this category, so an unpublished figure never outranks a published one.

    * Other unpublished figures are scored at the category median so missing data neither helps nor hurts.

    Weight capacity350 lb
    Warranty length12 yr
    Seat depth adjustmentNot listed
    Maximum seat heightNot listed
    Minimum seat heightNot listed
    Armrest adjustmentsNot listed
    Adjustable lumbarNot listed
    Forward tiltNot listed
    TiltAuto-Harmonic
    ArmsLeaf, height-adjustable, fixed or none
    Seat heightNot published by the maker
    PriceCheck price
    Check price at Amazon
    Specs source:

    How it compares

    Open the full comparison table

    Steelcase Leap
    8.5/10
    #1 · 4D arms, height-adjustable lumbar, 400 lb
    Humanscale Freedom Task Chair
    8.2/10
    #2 · Self-adjusting recline, 400 lb, 15-year warranty
    Haworth Soji XL
    8.1/10
    #3 · 24.5" wide seat warrantied to 600 lb
    Steelcase Series 1
    8.0/10
    #4 · Steelcase's value chair with 4D arms and 400 lb
    Steelcase Gesture
    7.8/10
    #5 · 360° arms built for devices, 400 lb
    Haworth Fern
    7.6/10
    #6 · Frameless back, optional 4D arms and forward tilt
    Haworth Zody
    7.5/10
    #7 · 4D arms, forward tilt, 16–21" seat
    Haworth Soji
    7.3/10
    #8 · Optional 4D arms, lumbar and forward tilt
    Herman Miller Embody
    6.5/10
    #9 · 3" of seat depth travel and fully adjustable arms
    Steelcase Karman
    6.1/10
    #10 · Light suspension chair with 4D arms
    Herman Miller Aeron (Size B)
    6.0/10
    #11 · The mesh benchmark, sized A/B/C
    Herman Miller Sayl
    6.0/10
    #12 · 350 lb rating with optional height-adjustable lumbar
    Herman Miller Lino
    5.7/10
    #14 · Optional seat depth and fully adjustable arms
    Branch Ergonomic Chair
    5.4/10
    #15 · 4" of seat depth travel for 5'2"–6'2"
    Branch Verve Chair
    5.0/10
    #16 · Knit chair with height-adjustable lumbar
    Sihoo Doro C300 Pro
    5.0/10
    #17 · Adds seat depth and 6D arms to the C300
    Hbada E3 Ultra
    5.0/10
    #18 · 2.76" of seat depth travel
    Hbada E3 Air
    4.9/10
    #19 · 330 lb mesh chair with 1.97" seat depth travel
    Sihoo B300 Pro
    4.5/10
    #20 · 4D lumbar and 6D arms
    Sihoo Doro S300
    4.5/10
    #21 · 6D arms with independent dynamic lumbar
    Sihoo Doro C300
    4.2/10
    #22 · Budget 4D arms, self-adaptive lumbar
    Branch Ergonomic Chair Pro
    4.0/10
    #23 · 5D arms, forward tilt and two-way lumbar
    Sihoo M57
    4.0/10
    #24 · Low-cost mesh chair with dual-adjustable lumbar