Sihoo M18 Review

The Sihoo M18 sells for $169.99 direct from Sihoo, down from a listed $289.99, and it packs a dual-adjustable lumbar pad, a 126 degree recline with a tilt lock, and a BIFMA tested 330 pound weight rating. Independent lab testing from TechGearLab scored it 66 out of 100, good for 9th place out of 18 chairs in that roundup, mostly because the casters roll stiffly and the armrests only move up and down.

If your budget tops out around $170 and lower back support is the feature you care about most, the M18 earns its price. If you need wider or angled armrests, or a chair that ranked closer to the top of a lab test, one of the two alternatives below is a better match.

Design and setup

The M18 measures 28 inches wide by 27 inches deep, with a height range of 44.09 to 51.18 inches once you account for the headrest and gas lift, according to Sihoo’s spec sheet. Seat depth is 17.91 inches and the maximum hip width is 20.08 inches, so it fits most adults but runs narrow for larger frames. The frame mixes steel, aluminum and nylon parts with a polypropylene back and headrest shell, and the whole chair weighs 37.1 pounds. TechGearLab’s testers finished assembly in 16 minutes but flagged unclear labeling on the hardware bags as a minor annoyance.

The mesh back and W shaped seat cushion are built for airflow rather than plush padding. The headrest slides 3.9 inches vertically and pivots 45 degrees, so it can support the base of the skull instead of just the neck. Before you buy, check that your desk height works with this chair’s range. Our desk height guide walks through how to match seat height to desk height so your elbows stay level with the keyboard.

How it scores

Adjustability (25%): 7.2/10. The M18 covers the basics: pneumatic seat height, a 126 degree recline with tilt lock, a pivoting headrest and armrests that move up and down. It stops short of the seat depth slider or the width adjustable armrests TechGearLab said were missing, which is why it lands in the middle of the pack rather than near the top.

Lower back support (25%): 8.5/10. This is where the M18 earns its keep. Sihoo describes the pad as dual-adjustable, moving both vertically and horizontally so you can dial in the curve of your own spine rather than settle for a fixed pad. TechGearLab called it a four-way lumbar system that is rare at this price and noted it competes with chairs that cost twice as much, though its testers said the adjustment knob takes real force to turn. For general guidance on chairs built around back support, see our best office chairs for back pain list.

Build and warranty (20%): 7.0/10. Sihoo backs the M18 with a 3 year warranty that activates automatically on purchases made directly through sihoo.com, covering manufacturing defects and structural failures under normal use. The frame passed BIFMA testing to 330 pounds. TechGearLab’s main quality complaints were stiff, hard to roll casters and armrests that felt hard under the forearm during long sessions.

Long sit comfort (15%): 7.5/10. TechGearLab’s panel reported roughly 7 hours of comfortable sitting on the M18, and one reviewer gave the seat cushion a perfect comfort score. The breathable mesh back keeps heat from building up, though the hard armrests were flagged as the one weak point for multi hour desk sessions.

3 year cost (15%): 9.0/10. At $169.99 with no filters, cushions or batteries to replace, the M18 is one of the cheaper ways to get dual-adjustable lumbar support in a mesh chair. See the math below.

These are researched picks built from brand specifications and independent lab data, not a chair we sat in ourselves. Read how we weigh every criterion on how we score.

The Practical Math

The Sihoo M18 is not a plug in product and Sihoo does not list any recurring parts for it, so the 3 year cost of ownership is just the purchase price.

• Chair: $169.99 one time, paid direct through sihoo.com.
• Consumables: none documented. There is no filter, battery or cushion replacement program listed on the product page.
• Electricity: not applicable. The M18 has no motor or power cord.

Total 3 year cost: $169.99. That is the whole calculation, and it is a big part of why the cost subscore lands at 9.0.

Alternatives

Two other mesh chairs stay under $250 and are worth cross shopping before you commit to the M18.

The Sihoo M57 sells for $239.99 on sihoo.com, down from a listed $319.99. It adds 3D armrests instead of the M18’s 2D version and carries the same 330 pound rating and 3 year warranty, so it is the pick if you specifically want armrests that also move in and out, not just up and down.

The Hbada P2 lists for $224.00 on hbada.com, down from $337.00. Hbada describes its lumbar system as a 5D design that adjusts through lateral twist, longitudinal pitch and vertical bend, and rates the chair to 330 pounds as well. It is worth a look if you want a lumbar pad that moves in more directions than the M18’s vertical and depth only adjustment, at a similar price.

If your budget stretches past $250, Sihoo’s own Doro C300 sells for $279.99 direct from Sihoo and adds a dynamic, weight responsive backrest the M18 does not have.

For a wider spread of price points, our best cheap office chairs list rounds up more options under $300.

Who should skip it

• Skip the M18 if you need armrests that pivot or shift width, since Sihoo’s own spec sheet lists them as up and down only.
• Skip it if a stiff lumbar adjustment knob would bother you daily. TechGearLab’s testers specifically flagged the force needed to turn it.
• Skip it if you roll your chair across carpet often. The casters tested as stiff and hard to glide on carpeted floors.
• Skip it if you need a chair rated above the middle of a lab test. TechGearLab’s 66 out of 100 score placed the M18 9th out of 18 chairs it tested.

FAQ

Does the Sihoo M18 help with back pain?

The M18’s lumbar pad adjusts vertically and in depth to support the natural curve of the lower back, and reviewers rate that system highly for the price. It is a posture support feature, not a treatment. If you deal with persistent back pain, talk to a physical therapist or doctor about what your spine actually needs before buying any chair.

What is the Sihoo M18’s weight capacity?

Sihoo rates the M18 to 330 pounds and says it passed BIFMA testing at that load, per the product’s spec sheet on sihoo.com.

Is the Sihoo M18 warranty worth relying on?

Purchases made directly through sihoo.com get a 3 year warranty that activates automatically and covers manufacturing defects and structural failures under normal use. Sihoo’s warranty page does not mention any free extension for registering the product. Buying through a third party marketplace may require proof of purchase for the same coverage.

How long does the Sihoo M18 take to assemble?

TechGearLab’s testers assembled the chair in about 16 minutes, though they noted the hardware bags were not clearly labeled, which slowed the process down slightly.

Is the Sihoo M18 better than the Sihoo M57?

The M57 costs about $70 more and upgrades to 3D armrests that move in and out, not just up and down. Both share the same 330 pound rating and 3 year warranty, so the choice comes down to whether armrest adjustment is worth the extra money to you.