SIHOO B100 vs SIHOO M59AS: Which Should You Buy?

Key difference: The B100 lists $250 lower, but the M59AS has 3D armrests where the B100 has 2D.

Every figure for the B100 and M59AS comes from SIHOO's own US, UK and EU stores, and prices are regular US list prices rather than sale prices; Chairpedia has not tested either chair.

Why compare them

Why put the SIHOO B100 next to the SIHOO M59AS? The B100 and M59AS are two lower-priced SIHOO chairs sold through SIHOO's own store, and shoppers often weigh one against the other before buying.

Specs side by side

Strengths and weaknesses

SIHOO B100

Strengths

• Lower list price: from $199.99 against $449.99 for the M59AS.
• Deeper recline: up to 135° against 126° on the M59AS.
• Choice of a mesh or a cushioned seat, which the M59AS's store listing does not offer.
• A Footrest Version is sold; none is listed for the M59AS.

Good to know

• If you like to fine-tune the arm pads, note these are 2D armrests, against 3D on the M59AS.

SIHOO M59AS

Strengths

• 3D armrests, against 2D armrests on the B100.

Good to know

• Compare the list prices first: it starts at $449.99, against $199.99 for the B100.
• If you lean far back, note it reclines up to 126°, against 135° on the B100.
• If you care about the seat material, note no seat-type choice is listed, unlike the B100.
• If you want a built-in footrest, look at the B100; no footrest version is listed for the M59AS.

How they differ

Price. At regular US list prices the SIHOO B100 is $199.99–$259.99 and the SIHOO M59AS is $449.99. The B100 lists $250 below the M59AS, before any store sale. Price options: the B100 — $199.99–$259.99; the M59AS — Black and White $449.99.

Armrests. The SIHOO B100 lists “Flip-up 2D armrests”, the SIHOO M59AS “3D coordinated flip-up armrests (flip up and down, left and right, forward and backward)”. With 3D armrests the M59AS lets you set the pads in more ways than the B100.

Recline. The SIHOO B100 lists “Up to 135°; positions at 110°, 125° and 135°”, the SIHOO M59AS “Up to 126°”. The B100 leans back further than the M59AS.

Seat options. The B100 is sold with a mesh or a cushioned seat; the M59AS's store listing has no seat-type choice.

Footrest. SIHOO sells a Footrest Version of the B100; no such version is listed for the M59AS.

Seat size. Seat height: the SIHOO B100 lists “18.3–21.9 in (≈46–56 cm)”, the SIHOO M59AS “18.31–22.24 in (46.5–56.5 cm)”. Seat width: the SIHOO B100 lists nothing, the SIHOO M59AS “19.88 in (50.5 cm)”. Seat depth: the SIHOO B100 lists nothing, the SIHOO M59AS “17.13 in (≈43.5 cm)”.

Other details. For the B100 and M59AS, the table above gives the headrest, lumbar support and chair weight in each brand's own wording.

Same on both. The B100 and M59AS list the same warranty (3 years) and maximum load (330 lb, ≈150 kg).

Who should buy which

• Pick the B100 over the M59AS if you want the lower price — the B100 lists $250 below the M59AS.
• Pick the B100 over the M59AS if you want a deeper recline (up to 135°).
• Pick the B100 over the M59AS if you want the choice of a mesh or a cushioned seat.
• Pick the M59AS over the B100 if you want 3D armrests rather than 2D.

Not published by the brand (B100 vs M59AS): seat depth and seat width for the SIHOO B100.

Sources

• SIHOO B100 (compared here with the M59AS): Sihoo B100 Ergonomic Office Chair With Flip-Up Armrest – EU Sihoo official Shop; Sihoo B100 Ergonomic Office Chair With Flip-Up Armrest – Official US Sihoo Store, checked 2026-10-08; US list price from SIHOO US Official Store, checked 2026-10-08.
• SIHOO M59AS (compared here with the B100): Sihoo M59AS Ergonomic Chair | Dual-Section Back & Flip-Up Armrests – UK Sihoo official Shop; Sihoo M59AS Ergonomic Office Chair with Dual-Section Backrest – Official US Sihoo Store, checked 2026-10-09; US list price from SIHOO US Official Store, checked 2026-10-09.
• Figures marked ≈ for the B100 and M59AS are Chairpedia's unit conversions, not brand figures.