The Sihoo M57 is a full-mesh chair for upright desk work, built around a firm lumbar pad you slide for height and wind in or out with a knob. Its backrest height is fixed, so that pad and the headrest do all the fitting. It suits sitters from about 160 to 185 cm, and the headrest is its weakest part.
- Sihoo rates the M57 for about 155–185 cm and 150 kg, and says it's tested to BIFMA standards and by SGS.
- It reclines to 126°, per Sihoo, and locks; the backrest height can't be adjusted.
- The lumbar pad slides up and down, and a round knob below it moves the pad in or out.
- The full-mesh seat has a padded front edge, a fixed depth of about 46 cm and an unloaded height of 42–52 cm.
- The headrest rises and tilts on one joint; Sihoo lists up to 10 cm of travel and 45° of tilt.
- It weighs 20.3 kg and comes in Black or Grey, with no footrest version in Australia.
Last updated October 2026. Specifications checked October 2026.
How does the Sihoo M57's lumbar support adjust?
The Sihoo M57's lumbar support adjusts two ways: slide the pad up or down for height, then turn the knob below it to push the pad forward or let it back. The pad is a separate, fairly hard block behind the mesh, so it presses harder than the backrest's gentle S-curve. Backed off, it barely touches; wound in, it presses firmly into the small of the back.
Stamped with Sihoo's logo, the knob sets how hard the pad presses. Height comes from sliding the pad.
Expect the height slide to be stiff and hard to fine-tune; on some chairs it creeps down instead, so check it before you sit. Start the knob halfway and wind forward; fully forward, the contact patch narrows and support can feel worse. Set carefully, this pad is the best reason to buy the M57.
Who does the Sihoo M57 fit, and where does it run out?
Sihoo rates the M57 for about 155–185 cm, and the fixed backrest shows at both ends of that range. The back reclines but can't rise or drop, so the lumbar pad and headrest must reach you on their own travel.
The back frame tilts as one piece. Nothing on it changes height except the lumbar pad and headrest.
| Height | What to expect |
|---|---|
| 150–159 cm | Feet may not sit flat at the lowest 42 cm seat; plan on a separate footrest |
| 160–164 cm | Usable, but the headrest can sit high even at its lowest |
| 165–169 cm | Seat and arms fit; the headrest can push the head forward |
| 170–179 cm | Middle of Sihoo's range and likely the easiest fit |
| 180–185 cm | Pad and headrest near the top of their travel; sit-test first |
| Over 185 cm | Above Sihoo's range; try the Sihoo DORO-C300 Pro V2 |
At about 185 cm the pad can sit a touch low even at the top of its slide, so push it all the way up and wind it in. Full measurements are in the M57's fit and dimensions.
Is the Sihoo M57's headrest any good?
The Sihoo M57's headrest suits some sitters and misses others, so it's the part most worth a sit-test. It rises and tilts on a single joint, in notches that can take some force and won't fine-tune.
The headrest rides on one post with one pivot, so it adjusts for height and angle only.
Sit bolt upright and your head usually won't reach it; lean back a little and it starts to work. It can sit high around 160 cm, push the head forward around 165 cm and stop short near 185 cm, and it can shift if you lean hard into it. It's removable, and the chair works without it, so treat it as a bonus, not a reason to buy.
How far does the Sihoo M57 recline?
The Sihoo M57 reclines to 126°, per Sihoo, and locks: enough to lean back between bursts of typing, not enough to lie back for a nap.
One paddle under the seat handles seat height and the recline lock. Pull it out to free the backrest; push it in to hold it. If it's locked reclined, lean back before releasing it, or the backrest tends to spring up fast.
The LIFT marking covers seat height; the same paddle pulls out and pushes in for the recline lock.
The 3D armrests rise, slide and swivel for mousing at an angle, but they don't follow you when you lean back to game or unwind. If you recline as much as you type, look at the two chairs below.
How does the Sihoo M57 seat feel over a long day?
The Sihoo M57's seat is wide, elastic mesh with a padded front edge, and it stays cooler than foam on a warm afternoon. It's about 51 cm across at the hips and fixed at about 46 cm deep, so check for a gap behind your knees. The mesh gives without feeling plush but can feel a little coarse to the hand.
Elastic mesh covers seat and back, with a strip of padding under the seat's front edge.
At around 100 kg, you may feel that front edge after four or five hours without a break. Black has black mesh on a black frame; the Grey version has light grey mesh on a white frame. Both sit on an aluminium base, per Sihoo. If a cool seat ranks first, compare our other mesh office chairs.
How should you set up the Sihoo M57?
Set the Sihoo M57 from the floor up, and do the lumbar pad before the headrest.
- Seat height: feet flat, knees about level with your hips (paddle marked LIFT).
- Lumbar height: pad to the hollow of your lower back.
- Lumbar firmness: knob halfway, then wind in until the pad presses.
- Arms: level with or just below the desk.
- Recline: pull the paddle out, lean back, push it in to lock.
- Headrest last: height, then angle, leaning back slightly.
Assembly takes about 15–20 minutes, and the 20.3 kg chair is easier to handle with two people.
Sihoo M57 or M57 Pro: what's actually different?
The Sihoo M57 Pro is the M57 rebuilt around movement, with a rising backrest, recline-linked arms, automatic tension and a 134° recline. The M57 keeps the bigger lumbar adjustment and the harder press.
| Feature | Sihoo M57 | Sihoo M57 Pro |
|---|---|---|
| Backrest height | Fixed | Four positions |
| Lumbar | Firm pad; more travel up, down, in and out | Wider pad that wraps the sides; presses less hard |
| Armrests | 3D: height, depth, swivel | 4D, linked to the recline |
| Headrest | Single joint: height and tilt | Double-jointed |
| Recline | 126° (per Sihoo), lockable | 134°, three lock positions |
| Seat | Mesh, padded front edge | Mesh over a foam layer |
Choose the M57 if you sit upright and want the firmer pad with more travel. Choose the M57 Pro if you recline often or need the backrest raised to lift the headrest, though very tall sitters may find a gap at the base of the raised backrest. Our M57, M57 Pro and C300 Pro V2 comparison sets all three side by side.
How does the M57 compare with the Sihoo DORO-C300 Pro V2?
The Sihoo DORO-C300 Pro V2 suits people who recline as much as they type; the Sihoo M57 suits people who mostly don't. On paper, the C300 Pro V2 adds a 7-notch backrest that glides as you lean back, a sliding seat, 8D arms that follow the recline, automatic tension and 135° of recline. Under about 170 cm that glide does little, as our DORO-C300 Pro V2 review explains.
The M57's pad is set entirely by hand, while the C300 Pro V2's adaptive pad moves with the backrest; pick the M57 if you'd rather set the press yourself. To lie well back, look across Sihoo's range: the Sihoo DORO-S300 is designed around a deeper recline.
What are the Sihoo M57's real drawbacks?
The Sihoo M57's two biggest drawbacks are its fixed backrest height, which leaves the lumbar pad and headrest short of travel near 185 cm, and a headrest that misses many sitters and can shift under pressure. The smaller ones:
- The lumbar slide tends to be stiff; on some chairs it creeps down instead.
- There's no seat depth adjustment or recline-linked arms, and the recline is a lean, not a nap.
- Under about 160 cm, feet may not reach the floor at the lowest seat height.
- It's solid and heavy, but the plastic frame is plain and the mould seams can show.
- The backrest can develop a slight wobble or creak with use. If yours does, contact us and we'll sort it.
Near the middle of Sihoo's height range, most of the fit problems fall away. Our best ergonomic office chairs guide lists alternatives by body size and how you sit.
FAQ
Does the Sihoo M57 have adjustable lumbar support?
Yes. The Sihoo M57's lumbar pad slides up and down for height, and a round knob below it pushes the pad forward or lets it back until it barely touches. The height slide tends to be stiff, so set it at the hollow of your lower back and check it before you sit.
What height is the Sihoo M57 suitable for?
Sihoo rates the M57 for about 155–185 cm. With a fixed backrest height, the ends of that range need care: under about 160 cm, check your feet reach the floor and the headrest isn't too high; over about 183 cm, the lumbar pad and headrest are near the top of their travel.
How far does the Sihoo M57 recline?
The Sihoo M57 reclines to 126°, per Sihoo, and locks with the paddle under the seat. That's enough to lean back between tasks, not to lie back for a nap, and there's no footrest version in Australia. If you recline often, compare it with the M57 Pro and the DORO-C300 Pro V2.
Does the Sihoo M57 have seat depth adjustment?
No. The Sihoo M57's seat is fixed at about 46 cm deep, though it's generous at about 51 cm across the hips. Sit right back and check for a gap behind your knees; if the seat edge presses there, a chair with a sliding seat will fit better.
Does the Sihoo M57 come with a footrest in Australia?
No. In Australia the Sihoo M57 is sold in Black or Grey without a pull-out footrest, and both colours come with the headrest. If your feet don't reach the floor at the lowest 42 cm seat height, use a separate footrest under the desk.
What is the difference between the Sihoo M57 and the M57 Pro?
The Sihoo M57 Pro adds a four-position backrest, a double-jointed headrest, 4D armrests linked to the recline, automatic tension and a 134° recline. The Sihoo M57 has a fixed backrest, 3D arms and a 126° recline (per Sihoo), but its lumbar pad has more travel and presses harder.
Where can you sit in the Sihoo M57?
The Sihoo M57 is on the floor at our Sydney showroom (Unit 11, 46-50 Wellington Rd, South Granville NSW) and our Melbourne showroom (Shop 1a/280 Whitehorse Rd, Nunawading VIC), alongside other Sihoo chairs and chairs from Herman Miller, LiberNovo, UE and HBADA. Book a visit or simply walk in during opening hours; our specialists Mick, Donald, Garrett and Kevin can set it to your height while you sit. We deliver across Australia.
