Last Updated: May 2026 | This review contains affiliate links. This costs you nothing and helps fund our independent research.

Quick Verdict

The SIHOO M57 is the best ergonomic chair under £300 available in the UK right now. It delivers adjustable lumbar support, 4D armrests, a breathable mesh back, and an included headrest at a price point where most competitors offer only one or two of those features. For home office workers, remote workers, and anyone spending six or more hours daily at a desk, it is the most defensible purchase in this category.

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Who Is the SIHOO M57 For?

Before getting into the detail, it helps to be clear about who this chair is and is not designed for.

The M57 is the right chair if you:

• Work from home and sit for six to ten hours daily
• Are experiencing lower back pain or postural fatigue from an inadequate chair
• Want genuine ergonomic adjustability without spending £500 or more
• Are buying your first serious ergonomic chair

The M57 is probably not the right chair if you:

• Prefer a very soft, heavily cushioned seat (the M57 is firm)
• Need a chair for a formal executive or client-facing environment (the aesthetic is functional rather than traditional)
• Are significantly over 120kg (check the weight rating before purchasing)

With that framing clear, here is a full breakdown of what the M57 actually delivers.

Build Quality and First Impressions

The M57 arrives flat-packed and assembles in approximately 20–30 minutes with the tools provided. The instructions are clear and the process is straightforward. Once assembled, the chair has a solid, well-engineered feel — the base is stable, the mechanisms engage cleanly, and there is no flex or creak in the backrest that would suggest poor construction.

The mesh back is taut and consistent, without the sagging that affects cheaper mesh chairs within the first year of use. The armrests, seat pan, and adjustment mechanisms all feel built to last rather than to impress in a showroom and deteriorate quickly.

SIHOO is a Chinese manufacturer that has established genuine credibility in the ergonomic chair market — the M57 carries BIFMA and SGS certifications, and the build quality reflects engineering standards rather than cost-cutting. For the price, the construction quality is meaningfully above what you would expect.

Adjustability — The Core Strength

This is where the M57 genuinely distinguishes itself from the competition at this price point. Most chairs under £300 offer basic height adjustment and perhaps a recline lock. The M57 offers a comprehensive adjustment system across every key dimension.

Lumbar Support

The lumbar support is independently adjustable in height — you slide it up or down to align it precisely with the inward curve of your lower back. This is the feature that matters most for back comfort, and the fact that it is fully adjustable rather than fixed puts the M57 ahead of the majority of chairs at this price.

The support itself provides firm, consistent pressure against the lumbar spine. It does not move dynamically with your body (that feature is found on the pricier Doro C300), but in the position you set it, it maintains contact reliably throughout the working day.

Headrest

The headrest adjusts in both height and angle — you can position it to support the cervical spine whether you are sitting upright or reclined. At this price point, an included adjustable headrest is genuinely unusual, and for anyone who reclines during calls, reading, or thinking, it is a worthwhile feature.

Armrests

The M57 features 4D armrests — adjustable in height, width, depth, and pivot angle. This level of armrest customisation allows proper shoulder and elbow positioning regardless of your desk height, arm length, or shoulder width. Correctly positioned armrests directly reduce upper back and neck tension, which often accompanies lower back pain in desk workers.

Seat Height and Recline

Seat height is pneumatically adjustable across a generous range suitable for most users. The recline mechanism offers adjustable tension — you can set the resistance to suit your preference — and locks at multiple angles. The recline range is comfortable for reading or thinking without feeling like the chair is tipping you backward.

Comfort Over a Full Working Day

Short-term comfort is easy to manufacture with enough foam padding. Long-term comfort — across a six to ten hour working day, day after day — requires proper ergonomic support. This is where the M57’s design philosophy proves itself.

The mesh back maintains consistent spinal contact throughout the day without creating pressure points. Unlike foam or leather backs that trap heat and cause the sweating and discomfort familiar to anyone who has used a standard office chair through a warm afternoon, the M57’s breathable mesh allows continuous air circulation. In UK home offices, where air conditioning is uncommon, this matters more than buyers often anticipate.

The seat cushion is firm. This is the most common point of adjustment for new M57 users, particularly those coming from padded leather chairs. The firmness is intentional — soft foam compresses and loses its structural support relatively quickly, leaving the user effectively sitting on a depleted base. The M57’s seat maintains consistent support over time. Most users adjust to the firmness within one to two weeks and subsequently find that they are significantly less fatigued at the end of the working day than they were in their previous chair.

For users who find the seat genuinely uncomfortable after the adjustment period, a thin memory foam seat cushion can be added without compromising the chair’s ergonomic function.

Lumbar Support in Practice

Because lumbar support is the single most important factor in chair-related back pain, it deserves more than a specification mention.

In practice, the M57’s adjustable lumbar support allows you to position firm, consistent contact at the exact point your lower back needs it. Once set correctly — which takes approximately five minutes and some experimentation — it maintains that position reliably. Sitting fully back in the chair with the lumbar support properly positioned, the natural inward curve of the lower spine is supported without effort. The back muscles can relax rather than contracting continuously to maintain posture.

For users who have been experiencing lower back pain from an inadequate chair, the improvement is typically noticeable within the first week of correctly configured use. The lumbar support does not fix existing spinal conditions, but it removes the sustained mechanical stress that causes and perpetuates the most common forms of desk-related back pain.

How It Compares to the Competition

SIHOO M57 vs CLOUVOU Clever Seat

The Clever Seat offers more comprehensive adjustability — wider armrest range, adjustable seat depth, and a more refined overall system. It costs significantly more. For users who need maximum customisation or have proportions that standard chairs cannot accommodate, the Clever Seat is worth the premium. For most users, the M57’s adjustment range is sufficient and the price difference is substantial.

SIHOO M57 vs SIHOO Doro C300

The Doro C300 is SIHOO’s step-up model, featuring a dynamic lumbar support system that moves with the user rather than staying fixed. For users who shift position frequently throughout the day, this is a meaningful improvement. The C300 costs more and is the natural upgrade path if the M57’s fixed lumbar support proves limiting.

SIHOO M57 vs Hbada Ergonomic Chair

The Hbada is a budget alternative at a lower price point. It offers less adjustability, less robust construction, and a less effective lumbar system. For users who cannot stretch to the M57, the Hbada is a credible option — but the gap in ergonomic performance is real and noticeable over a full working day.

SIHOO M57 vs Herman Miller Aeron

The Aeron is the benchmark ergonomic chair and costs four to five times more than the M57. It offers superior materials, a more refined dynamic support system, and significantly better long-term durability. If budget is not a constraint, the Aeron is a better chair. For the majority of UK home office workers, the M57 delivers 80% of the ergonomic benefit at 20% of the cost, which makes it the rational choice for most buyers.

Setup and Adjustment Guide

Getting the M57 set up correctly is essential. An improperly adjusted M57 will underperform; a properly adjusted one will outperform chairs costing twice as much.

Seat height: Adjust until your feet are flat on the floor, thighs roughly parallel to the ground, and knees at approximately 90 degrees. If this position puts the desk too high for comfortable arm positioning, a footrest is the solution.

Lumbar height: Sit fully back into the chair. Adjust the lumbar support up or down until it presses firmly and comfortably into the inward curve of your lower back — typically between your waistband and the bottom of your ribcage. If you are unsure, place your hand behind your lower back to locate the curve, then position the support there.

Armrest height: Set so your forearms rest lightly on the armrests with shoulders relaxed and elbows at approximately 90 degrees. If your shoulders rise toward your ears, lower the armrests. If you are hunching to reach them, raise them.

Armrest width and angle: Adjust inward until the armrests are directly below your elbows in your natural working position. Pivot the angle if needed so your forearms rest naturally without twisting.

Headrest: Position so it contacts the back of your head or neck in your natural sitting or reclined position. Adjust the angle so it provides support rather than pushing your head forward.

Recline tension: Adjust so the chair offers slight resistance when you lean back. Sit in your normal working position and make small movements — the chair should feel responsive without being unstable.

Allow one to two weeks before assessing whether the chair is working. Postural muscles that have been under strain take time to adapt to proper support.

Potential Drawbacks

Seat firmness. As noted, the M57 is not a plush chair. Users who strongly prefer cushioned seating will need an adjustment period, and some may find the seat uncomfortable longer term. This is a minority experience but worth flagging.

Armrest padding. The armrest padding is adequate but not luxurious. For users who rest their forearms heavily on armrests for extended periods, aftermarket armrest pads are available and inexpensive.

Weight limit. Check the manufacturer’s stated weight limit before purchasing. Users at or above this threshold should consider alternatives designed for higher weight ratings.

Aesthetics. The M57 is a functional ergonomic chair. It looks like one. If your workspace is client-facing or you have a strong preference for a traditional executive aesthetic, it may not suit the environment.

Final Verdict

The SIHOO M57 is the strongest ergonomic chair available in the UK under £300, and for most home office and remote workers it is the correct answer to the question of which chair to buy. Its adjustable lumbar support, 4D armrests, breathable mesh back, and included headrest represent a feature set that was not available at this price point until relatively recently, and SIHOO’s build quality has proven reliable across a large installed base of UK users.

It is not perfect. The seat firmness requires adjustment, the aesthetics are functional rather than refined, and users wanting dynamic lumbar support or maximum adjustability will find better options at higher price points. But for the core job it is designed to do — supporting a desk worker through a long day without causing or worsening back pain — it does it well, consistently, and at a price most people can justify.

Rating: 4.5 / 5

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Specifications Summary

Frequently Asked Questions

Is the SIHOO M57 good for back pain? Yes, for most users. The adjustable lumbar support addresses the primary mechanical cause of chair-related lower back pain, and the full ergonomic adjustment system allows a properly configured sitting position. Users with significant or clinical back conditions should consult a physiotherapist, but for typical desk-related back pain the M57 is one of the most effective solutions under £300.

How long does the SIHOO M57 last? With normal daily use, the M57 is built to last four to five years. The mesh back maintains its tension well, and the mechanisms are robust. SIHOO’s warranty covers manufacturing defects — check the current terms at point of purchase on Amazon UK.

Is the SIHOO M57 easy to assemble? Yes. Assembly takes approximately 20–30 minutes with the tools provided. The instructions are clear and most users complete it without difficulty.

Does the SIHOO M57 work for tall people? The M57 works well for users of average to above-average height. Very tall users (above 6’3″ / 190cm) may find the seat height and back length limiting — the CLOUVOU Clever Seat or a chair specifically designed for taller users may be a better fit. See our guide to the best ergonomic chairs for tall people in the UK.

Is the SIHOO M57 available with fast delivery in the UK? Yes — the M57 is available on Amazon UK with Prime delivery. Stock levels fluctuate, so check current availability before purchasing.

What is the weight limit of the SIHOO M57? Check the current product listing on Amazon UK for the stated weight limit, as specifications can vary between versions. If you are near or above the limit, consider a chair rated for higher capacity.

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