FlexiSpot Soutien Ergonomic Office Chair (C5) vs SIHOO M18

Side by side from official specifications, sourced prices and User Insights. No written comparison exists for this pair yet.

FlexiSpot Soutien Ergonomic Office Chair (C5)

FlexiSpot

FlexiSpot Soutien Ergonomic Office Chair (C5)

$249.99 – $279.99

VS
SIHOO M18

SIHOO

SIHOO M18

$289.99 – $299.99

2 years

longer warranty on FlexiSpot Soutien Ergonomic Office Chair (C5) than SIHOO M18 (official terms)

Differences at a glance

FlexiSpot Soutien Ergonomic Office Chair (C5)SIHOO M18
Price
$249.99 – $279.99$289.99 – $299.99
Seat height
17.9–20.9 in44–54 cm
Seat depth
18.7 in17.91 in (≈ 45.5 cm)
Load capacity
300 lb330 lb (≈ 150 kg)
Recline
95–115°Maximum 126° recline angle
Arms
2DAdjustable armrests (Up and down)
Headrest
2DHeadrest moves 3.9" up and down and pivots 45°
Lumbar support
2DLumbar support adjusts vertically and horizontally
Warranty
5 years3 years

Questions

Which is cheaper, the FlexiSpot Soutien Ergonomic Office Chair (C5) or the SIHOO M18?

The FlexiSpot Soutien Ergonomic Office Chair (C5) is cheaper to start: $249.99 versus $289.99 for the SIHOO M18 at the brand stores (Oct 2026).

Which has a higher weight capacity?

The SIHOO M18, rated for 330 lb versus 300 lb for the FlexiSpot Soutien Ergonomic Office Chair (C5).

Which has a headrest?

Both: the FlexiSpot Soutien Ergonomic Office Chair (C5) as standard and the SIHOO M18 as standard.

FlexiSpot Soutien Ergonomic Office Chair (C5): specs, reviews, where to buy →SIHOO M18: specs, reviews, where to buy →

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