• Sihoo M18 Classic Office Chair With Triple Spinal Relief - Official US Sihoo Store
  • Sihoo M18 Classic Office Chair With Triple Spinal Relief - Official US Sihoo Store
  • Sihoo M18 Classic Office Chair With Triple Spinal Relief - Official US Sihoo Store
  • Sihoo M18 Classic Office Chair With Triple Spinal Relief - Official US Sihoo Store
  • Sihoo M18 Classic Office Chair With Triple Spinal Relief - Official US Sihoo Store
  • Sihoo M18 Classic Office Chair With Triple Spinal Relief - Official US Sihoo Store
  • Sihoo M18 Classic Office Chair With Triple Spinal Relief - Official US Sihoo Store
  • Sihoo M18 Classic Office Chair With Triple Spinal Relief - Official US Sihoo Store
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Sihoo M18 Ergonomic Office Chair with Soft Cushion & Spine Support

Sihoo M18 Ergonomic Office Chair with Soft Cushion & Spine Support

4.9
Rated 4.9 out of 5 stars
395 Reviews

"With the new height I chose, my attempts at maintaining my posture are literally better-supported." Victoria Rose, from MMORPG

$249.99
$249.99
Sale Sold out
Taxes included. Free shipping.
Color: Black

Product Description

The Sihoo M18 Ergonomic Chair combines soft comfort with breathable support, turning long hours at your desk into effortless relaxation.

Key Features

Ergonomic design: Soft, cushioned seat and breathable mesh backrest keep you cool and comfortable for hours

Adjustable support: Height-adjustable armrests and 2D lumbar support adapt perfectly to your posture

Relax with ease: Reclines up to 126° for effortless rest between tasks

Built to last: Supports up to 330 lbs and certified by BIFMA for trusted durability

Trusted by experts: Endorsed by Creativebloq, TechRadar, GamingTrend, MMORPG, and more

Assembly Instruction

View assembly instructions 1/1 (PDF)

Materials

Headrest
Crafted from high-strength PP (polypropylene) for durability and flexibility, the headrest features adjustable height and rotation to provide personalized neck support.

Backrest
Made of resilient PP material in an ergonomic S-shaped frame that follows the natural curve of the spine, offering stable and adaptive back support for long sitting sessions.

Lumbar Support
Built with sturdy PP and wrapped in thick, high-density foam to deliver strong, dynamic lower-back reinforcement.

Mesh
Premium polyester mesh that’s breathable, fade-resistant, tear-proof, and UV-resistant — ensuring cool comfort and long-lasting use.

Seat
Constructed with multi-layer wood board and medium-soft virgin foam for balanced comfort and reliable support.

Mechanism
Cold-rolled steel structure with a three-level tilt lock system and adjustable tension control, engineered for durability three times longer than standard mechanisms.

Armrests
Steel and nylon frame with a soft PU surface; height-adjustable design provides smooth touch and ergonomic arm support.

Gas Lift
SGS- and BIFMA-certified for safe, stable, and reliable height adjustment.

Casters
Smooth, silent, and floor-safe wheels with rounded edges that prevent scuffing while allowing easy movement.

Base
Detachable electroplated iron base, BIFMA-certified for strength, balance, and long-term stability.

Promise

30-Day Free Returns: Try the chair for 30 days. If it’s not for you, feel free to return it.

3-Year Warranty: Enjoy lasting comfort and peace of mind with our 3-year warranty.

Satisfaction Guarantee: For any issues, contact casupport@sihoo.com for prompt assistance and guaranteed satisfaction.

  • Overcome sitting pain
  • Save money
  • Enhance workplace
  • Sustainable development
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Details

Comparison

Review

Sihoo M18
Color:
$249.99
$249.99
Sale Sold out
4 reasons to love Sihoo M18 Ergonomic Chair
Made for every moment
Made for every moment
From focused work to relaxed reading, the M18 keeps you comfortable in any setting.
Adjustable comfort
Adjustable comfort
Easily adapts to different body shapes, giving you personalized comfort in any position.
Soft, spacious seat
Soft, spacious seat
A wide W-shaped cushion offers soft, balanced comfort that lasts all day.
Quiet and floor-friendly
Quiet and floor-friendly
Smooth, silent casters glide easily without scratching or damaging your floors.
 

For every part of you

Enhance your posture, relieve your stress—sit well and work better.

2D Adjustable Headrest
The soft, single-joint headrest smoothly adjusts through 8 height levels and tilts 45° up or down, perfectly aligning with your neck and head in any sitting posture.
2D Adjustable Lumbar Support
Easily rotate the knob directly behind you to move the lumbar support forward or backward, or lift it up and down through 7 height settings to find your ideal lower back position.
1D Adjustable Armrest
Press and hold the side latch to raise or lower the armrests by up to 2.8 inches (7cm), with a 1.6-inch-thick and 4-inch-wide pad that keeps your arms relaxed.
3-Stage Adjustable Recline
Switch between three lockable recline angles — 110°, 118°, and 126°, simply by pulling the side lever about 0.4 inches (1 cm) outward to activate your preferred lean.

Find Your Best Fit

Product
Sihoo M18 Classic Office Chair With Triple Spinal Relief - Official US Sihoo Store
$249.99
$249.99
Sale Sold out
Sihoo M57 Full Mesh Breathable Office Chair for Sedentary Lifestyle - Official US Sihoo Store
$269.99
$269.99
Sale Sold out
Sihoo M102C Ergonomic Office Chair with Customizable Lumbar Support - Official US Sihoo Store
$229.99
$229.99
Sale Sold out
Name M18 M57 M102C
Budget-friendly everyday comfort Budget-friendly everyday comfort Classic breathable ergonomic support Everyday foam-seat support with more flexibility
Key Differences Foam seat, height-adjustable armrests Mesh seat, 3D adjustable armrests Foam seat, flip-up armrests
Seat Feel Softer cushioned comfort Cooler breathable support Softer cushioned comfort
Support Style Simple and cushioned Balanced and breathable Soft and space-friendly
product weight 37.1 lbs 44.8 lbs 31.8 lbs
assembly Requires assembly Requires assembly Requires assembly
weight capacity 330 lbs 330 lbs 330 lbs
guarantee (3) years warranty (3) years warranty (3) years warranty
Choose It If… You want an affordable ergonomic upgrade You want breathable daily support with essential adjustments You want a soft foam seat with a more flexible, space-saving setup

Find Your Best Fit

Sihoo M18 Classic Office Chair With Triple Spinal Relief - Official US Sihoo Store
$249.99
$249.99
Sale Sold out
Sihoo M57 Full Mesh Breathable Office Chair for Sedentary Lifestyle - Official US Sihoo Store
$269.99
$269.99
Sale Sold out
Name
M18
Name
M57
Budget-friendly everyday comfort
Budget-friendly everyday comfort
Budget-friendly everyday comfort
Classic breathable ergonomic support
Key Differences
Foam seat, height-adjustable armrests
Key Differences
Mesh seat, 3D adjustable armrests
Seat Feel
Softer cushioned comfort
Seat Feel
Cooler breathable support
Support Style
Simple and cushioned
Support Style
Balanced and breathable
product weight
37.1 lbs
product weight
44.8 lbs
assembly
Requires assembly
assembly
Requires assembly
weight capacity
330 lbs
weight capacity
330 lbs
guarantee
(3) years warranty
guarantee
(3) years warranty
Choose It If…
You want an affordable ergonomic upgrade
Choose It If…
You want breathable daily support with essential adjustments

Customer Reviews

4.9
Rated 4.9 out of 5 stars
Based on 395 reviews
99%would recommend this product
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395 reviews
  • NE
    Nolan E.
    Verified Buyer
    I recommend this product
    Rated 5 out of 5 stars
    2 months ago
    5 Stars

    I use this chair every day in front of my desk and frankly it is really comfortable. The seat is pleasant and even when I stay on it for a long time, I am well settled.

    Was this helpful?
  • JB
    Jace B.
    Verified Buyer
    I recommend this product
    Rated 5 out of 5 stars
    2 months ago
    5 Stars

    In summary, it is an excellent chair dedicated to office automation and teleworking. It perfectly combines the comfort of a semi-firm padded seat and the breathable freshness of a mesh backrest. Strong, easy to assemble and has great lumbar support

    To be recommended.

    Was this helpful?
  • BB
    Bruce B.
    Verified Buyer
    I recommend this product
    Rated 5 out of 5 stars
    2 months ago
    5 Stars

    This chair is heavier than expected, with solid materials, and is relatively easy to assemble. It has a simple and elegant design, is quite comfortable to sit in, and the wheels are of good quality, gliding smoothly and quietly in all directions. It offers great value for money.

    Was this helpful?
  • XH
    Xavier H.
    Verified Buyer
    I recommend this product
    Rated 5 out of 5 stars
    2 months ago
    5 Stars

    Very good, really comfortable does not make you sweat

    Was this helpful?
  • AB
    Anthony B.
    Verified Buyer
    I recommend this product
    Rated 5 out of 5 stars
    2 months ago
    5 Stars

    Been using it for almost 3 years. Still solid as day one.

    Was this helpful?

Frequently asked questions

Where do you ship?

We ship directly from our local Canadian warehouses for fast delivery and smooth service.

Do I need to pay customs or import fees when ordering from Canada?

No worries, Sihoo has two local warehouses in Canada, so your order ships domestically with no customs or import fees.

Is the 30 day trial risk free?

Yes! Every Sihoo chair purchased from our official Canadian website includes a 30-day risk-free trial.

Try it in your home or office, and if you’re not completely satisfied, simply contact us within 30 days for a full refund. No hidden fees, no catch.

What is Sihoo's return policy?

You can return your chair within 30 days of receiving it for any reason. We’ll arrange the return process and refund your purchase once the product is received back in its original condition and packaging.

What is included in the 3 year warranty?

All Sihoo chairs are backed by a 3-year limited warranty, covering manufacturing defects in materials and workmanship under normal use.


This includes the frame, base, casters, gas lift, and mechanism components.

How long does it take to assemble the M18 chair?

Assembly is quick and easy, most users finish in about 15–20 minutes with the included tools and instructions.

What are the size and weights of the packaging?

Each Sihoo M18 ships in one securely packed box for easy handling.


Approximate dimensions and weight:
Box Dimensions: 27.6" × 10.8" × 21.1" (70 × 27.5 × 53.5 cm)
Shipping Weight: 42.9 lb (19.5 kg)

Why SIHOO？
We’re in the business of making sitting good
Ergonomic Design
Ergonomic Design
Designed to support healthy posture, reduce strain, and keep you comfortable all day.
Durable Build
Durable Build
Built to last with durable materials and precise engineering for long-term reliability.
Trusted Worldwide
Trusted Worldwide
Sihoo is trusted in over 100 countries, with millions of chairs sold globally every year.