Last Updated: May 2026 | Some links on this page are affiliate links. This costs you nothing and helps fund our independent research.
Both the Clouvou Clever Seat and the SIHOO M57 appear consistently at the top of ergonomic chair recommendations in the UK under £500. They are legitimately good chairs — well-built, breathable mesh backs, adjustable lumbar support, and proven track records among UK buyers. If you are deciding between them, you are already looking in the right place.
The question is which one is right for your specific situation. The answer is not the same for everyone, and this comparison gives you the honest picture rather than simply declaring a winner.
Quick Answer
Choose the Clouvou Clever Seat if you work eight to ten hours daily, need seat depth adjustment, or have found that other chairs cannot be adjusted to fit your body correctly.
Choose the SIHOO M57 if you want the strongest ergonomic performance at the lowest price, work six to eight hours daily, and have average body proportions.
👉 Check Clouvou Clever Seat on Amazon.co.uk →
👉 Check Sihoo M57 Price on Amazon.co.uk →
Side-by-Side Comparison
| Feature | Clouvou Clever Seat | SIHOO M57 |
|---|---|---|
| Lumbar support | Height + depth adjustable | Height adjustable |
| Armrests | 4D — full range | 4D — standard range |
| Seat depth | Adjustable | Fixed |
| Headrest | 3D — height, depth, angle | Height + angle |
| Recline | Multi-angle, adjustable tension | Multi-angle, adjustable tension |
| Back material | Breathable mesh | Breathable mesh |
| Build quality | ⭐⭐⭐⭐☆ | ⭐⭐⭐⭐ |
| Best for | 8–10 hour sessions, full adjustability | 6–8 hour sessions, best value |
| Price range | £300–£450 | £180–£300 |
Where They Are the Same
Before covering the differences it is worth being clear about what both chairs share, because the marketing around this comparison often overstates the gap.
Both chairs have breathable mesh backs that provide good airflow during long sessions — neither will cause the heat buildup associated with leather or foam alternatives. Both have adjustable lumbar support that addresses the primary mechanical cause of desk-related back pain. Both have 4D armrests that allow proper shoulder and elbow positioning. Both are well-built for their respective price points and have established positive reputations among UK buyers.
For users whose primary concern is whether either chair is ergonomically adequate — the answer is yes, both are. The question is which is the better fit for your specific body and working pattern.
The Real Differences — What Actually Matters
1. Seat Depth Adjustment
This is the most significant practical difference between the two chairs and the feature most likely to determine which is the right choice for you.
The Clouvou Clever Seat has an adjustable seat pan that slides forward and backward. The SIHOO M57 does not — its seat depth is fixed.
Why does this matter? Seat depth determines whether you can sit fully back in the chair — maintaining lumbar contact — while your knees clear the front edge without restriction. If the seat is too long for your leg length, you face a constant compromise: either lose lumbar contact by sliding forward, or have the seat edge pressing into the back of your knees. Neither is ergonomically acceptable over a full working day.
For users with average leg length, the M57’s fixed seat depth is typically adequate. For shorter users, taller users, or anyone who has consistently found that chairs either push into the back of their knees or require them to sit away from the backrest, the Clever Seat’s adjustable seat depth resolves this directly.
Verdict: If seat depth is a concern for you, the Clever Seat is the clear choice. If you have average proportions and have not experienced this issue with other chairs, the M57’s fixed depth is unlikely to be a problem.
2. Lumbar Support
Both chairs offer height-adjustable lumbar support. The Clever Seat adds depth adjustment — the ability to bring the lumbar pad closer to or further from your spine.
In practice, this matters most for users with a pronounced lumbar curve who find that standard lumbar pads do not make adequate contact with their spine, and for users who sit at different distances from the backrest throughout the day. For users with a typical lumbar curve who sit consistently fully back in the chair, the M57’s height-adjustable lumbar support is sufficient.
Verdict: The Clever Seat’s depth adjustment is a genuine improvement for users who need it. For most users with average spinal curvature, the M57’s lumbar system is effective.
3. Armrest Range
Both chairs have 4D armrests, but the Clever Seat’s range of movement is wider — particularly in the width dimension, which allows accommodation of both narrower and broader shoulder widths than the M57’s standard range covers.
For users with average shoulder width, both chairs provide adequate armrest positioning. For users at the narrower or broader end of the range, the Clever Seat’s additional width adjustment is worth having.
Verdict: Marginal advantage to the Clever Seat for users with non-standard shoulder width. Equal for average users.
4. Price
The SIHOO M57 is available on Amazon UK for £180–£300. The Clouvou Clever Seat is £300–£450. The gap is real and meaningful.
For the additional cost of the Clever Seat, you get seat depth adjustment, lumbar depth adjustment, and a wider armrest range. Whether that justifies the premium depends entirely on whether you need those features. For users who do not specifically need seat depth adjustment — the most impactful of the three differences — the M57 delivers 85–90% of the Clever Seat’s ergonomic performance at a significantly lower price.
Verdict: The M57 is better value for most users. The Clever Seat is worth the premium for users who specifically need its additional features.
Long-Session Comfort: 8–10 Hours Daily
For users working very long hours, the Clever Seat has a modest advantage — not because its mesh or cushioning is meaningfully different, but because the comprehensive adjustment system allows a more precisely configured sitting position. Over eight to ten hours, small misalignments in lumbar position, armrest height, or seat depth accumulate into significant discomfort. The Clever Seat’s wider adjustment range reduces the likelihood of these misalignments persisting uncorrected.
That said, the SIHOO M57 is not inadequate for long sessions. Many UK users work eight-hour days in the M57 comfortably. The Clever Seat’s advantage at this use level is real but not dramatic for users who have configured the M57 correctly.
Who Each Chair Is Actually For
The SIHOO M57 is the right chair if you:
- Have average body proportions and have not experienced seat depth issues with other chairs
- Work six to eight hours daily
- Want the strongest ergonomic specification available under £300
- Are buying your first serious ergonomic chair and want proven reliability at a lower price
👉 Check Sihoo M57 Price on Amazon.co.uk →
The Clouvou Clever Seat is the right chair if you:
- Work eight to ten hours daily and want maximum ergonomic precision
- Are shorter or taller than average and need seat depth adjustment
- Have found that other ergonomic chairs cannot be adjusted to fit your body correctly
- Have a pronounced lumbar curve that standard lumbar pads do not adequately support
- Can justify the additional cost against your daily hours of use
👉 Check Clouvou Seat Price on Amazon.co.uk →
The Honest Verdict
The Clouvou Clever Seat is the more capable chair. Its seat depth adjustment, wider armrest range, and lumbar depth adjustment are genuine improvements over the SIHOO M57 that make a real difference for the users who need them.
The SIHOO M57 is the more rational purchase for most buyers. The features the Clever Seat adds over the M57 matter significantly for some users and barely at all for others. If you have average proportions, work six to eight hours daily, and have not experienced seat depth or lumbar contact issues with previous chairs, the M57 delivers the ergonomic fundamentals effectively at a price that is £100–£150 lower.
The practical question is simple: do you specifically need seat depth adjustment? If yes, buy the Clever Seat. If not, buy the M57 and invest the difference elsewhere — a monitor arm, a footrest, or saving toward a standing desk.
Frequently Asked Questions
Which is better — Clouvou Clever Seat or SIHOO M57? The Clouvou Clever Seat offers more comprehensive adjustability, particularly seat depth and lumbar depth. For users who need these features it is the better chair. For users with average proportions working six to eight hours daily, the SIHOO M57 delivers strong ergonomic performance at a meaningfully lower price.
Is the Clouvou Clever Seat worth the extra cost over the M57? If you need seat depth adjustment or wider armrest range — yes, clearly. If you have average proportions and have not experienced fit issues with standard chairs, the M57 is likely sufficient and the price difference is better spent elsewhere.
Is the SIHOO M57 good for long hours? Yes, for most users working six to eight hours daily. For eight to ten hour sessions where maximum ergonomic precision matters, the Clever Seat’s wider adjustment range provides a modest but real advantage.
Which chair is better for back pain? Both address the primary cause of desk-related back pain through adjustable lumbar support and breathable mesh construction. The Clever Seat’s lumbar depth adjustment makes it marginally more effective for users with pronounced lumbar curves or specific fit requirements. For typical desk-related back pain, both chairs are effective when properly configured.
Which chair lasts longer? Both are built to last four to five years with daily use. The Clever Seat’s slightly heavier construction suggests marginally better long-term durability, but both represent solid build quality at their respective price points.
