RH Logic 400

Product Code: RH-LG400

The RH logic 400is one of the world's most popular ergonomic office chairs. It has a range of ergonomic features and proven durability. It has been designed for the workplace, both to prevent musculoskeletal injuries and as a remedial chair for individuals with specific injuries. Indeed, the chair has become our most highly requested product for individuals with a wide range of back problems

The chair suits a diverse range of shapes and sizes and can be used in a variety of work environments. Central to the success of this chair is its high degree of ergonomic adjustability that enables you to fit the chair to your own shape and size. For more details on the features please select the features tab below.

Please note that the 400 is more suitable for individuals over 5ft 6. Any users under 5ft 6 please see the 300.

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Excl. VAT: £787.49 Incl. VAT: £944.99

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Excl. VAT: £787.49 Incl. VAT: £944.99

RH Logic 400 black

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RH Logic 400

The RH Logic 400 has a high backrest (for the taller user) and extra padding providing support between the shoulders. The backrest narrows towards its top to allow greater freedom of movement for the arms. The seat includes a layer of wool, providing improved ventilation and making it cooler than conventional pads. Its waterfall edge reduces pressure on the underside of the thighs.

Alongside the full set of independent adjustments that you come to expect with an ergonomic seat, the Logic 400 incorporates a free floating tilting mechanism which allows the seat to move as you move . The chair has a range of lever adjustments. For a full list of these adjustments please see the features tab.

It is also possible to customise these chairs to your requirements. Please click on the drop down boxes to see all the options. The model suits a wide range of body shapes and sizes. If you are particularly petite or large we may need to adapt the chairs and so please contact us to discuss this as well as 24/7 applications.

We understand that there are a large range of options available for the chair and so why not take us up on a free telephone consultation where an ergonomics consultant will take you through all the options available. You can contact us by calling 0203 0510157 or email us for further information.

The range explained

The Logic 4 and 3 are the original models. The 400 and 300 models were then developed as the new versions of the 4 and 3 respectively. All the chairs have almost identical functionality but there are some small differences worth noting. The Logic 4 and 3 have their levers on the underside of the seat, whilst the 400 and 300 have easily accessible buttons on the side. It's easy to replace the pads on the 400 and 300 (snap function) but more difficult on the 4 and 3 (the chair has to go back to our warehouse). Finally, the seat on the 300 and 400 has a layer of wool, providing extra ventilation. The main difference between 400 and 300 is that the backrest is higher on the 400 which tends to be more popular with taller individuals (over 5ft 6). Within the range you can also get the Elegance version of each chair. The only difference between the Elegance and the standard versions is that the Elegance comes with an upholstered back as standard. You can select the upholstered version from the drop down options. If you are still not sure about the model that you need please contact us

What we like/what customers like

Alongside the 300, the RH Logic 400 is arguably the most popular remedial ergonomic chair in the UK. The high back has made the chair particularly popular for adults with low back pain and neck pain. We are very confident in the durability of these chairs and have experienced very few issues with them.

Ergonomic Adjustability

  • Seat height adjustability
  • Seat depth adjustability
  • Independent back rest adjustability
  • Backrest height adjustablity
  • Full seat rocker – using patented 2PP technology
  • Seat tilt tension
  • Height, width, depth adjustable arms as an optional extras
  • Height, width and rotational arms as an optional extra
  • Inflatable lumbar support


  • Built to fit in with almost any other set of chairs


  • Precision engineered backed by a 10 year guarantee


  • Made from recycled materials
  • Components of the chair are 100 per cent recyclable
  • EN 1335 and BS 5459:2 certification


  • Seat Height Range (standard gas lift): 410 - 530mm
  • Seat Width: 475mm
  • Seat Depth Range: 400 - 460mm
  • Armrest Height Range: 210 - 290mm
  • Armrest Width Range: 375 – 505mm
  • Backrest Height: 620mm
  • Backrest Width: 440mm
  • Height of Foremost Support Point on Back Pad and Adjustment Range: 195 - 270mm
  • Height of Foremost Support Point on Headrest and Adjustment Range: -
  • Maximum Chair Width: -
  • Footbase diameter: 660mm
  • Weight of Item: 21.8kg

Key Measurements to take for chair sizing

The ideal measurements needed to help us ensure that the chair will fit are listed below.

  • Thigh length
  • Popliteal height
  • Hip Width
  • Distance between inside of elbows
  • Elbow height from the seat pan
  • Shoulder height from seat pan
  • Mid point of lumbar spine to seat pan

We understand that not all measurements are recorded and so if you don’t have all these measurements just contact one of our ergonomic specialists.

RH Adjustability Animation

RH Instruction Video

Some download links here.

Dave Rodgers, Kent

I was recommended backrest by a physiotherapist. The chair was expensive so not sure at first and so I had the chair on a trial basis. I wasn’t sure what to think when the chair arrived as it looked like a normal black chair. It was only when I sat on the chair that I really noticed the difference. Immediately the chair felt like it fitted me and was such a vast improvement. It is still early days but the chair is great and the service provided by Fluto was exemplary

Jen Perrin, London

I purchased the RH Logic 400 after trying out a colleague's chair at work. After having some time to use the chair I can safely say that is is the most comfortable chair that I have ever sat on. I am a fidgetter and so I love the fact that I can unlock the chair and gently rock while I work. I also got a neck rest with the chair but don't really use this. Overall excellent chair, excellent service

John Brown, London

We recently purchased an RH 400 for one of our members of staff in the office. The chair arrived very quickly and the chair was very comfortable. Having had the chair for 2 weeks I am pleased to say that the staff member has found it very comfortable and it has resolved a number of the problems that they were experiencing. I would definitely recommend the chair

Peter David, Surrey

Love the chair ----- incredibly comfortable, will not be going back to the old one.

Joanne Edwards, London

I ordered the chair to help with an issue in my neck and back pain. When I first got the chair it felt comfortable but quite firm. Over the next 2 weeks I got used to the firmness and whilst I still have some neck pain it is significantly reduced, and my back is much more comfortable. Whilst the chair is brilliant I have also made some major changes to the way that I work including taking 30 minute stretch breaks and moving more whilst in the chair. Overall, very happy.

David Adams,Chester

I was recommended a 400 for help with my sciatica. When I first got the chair I was a bit overwhelmed by the number of levers but after my training session with Fluto I was able to pick up the key levers. The chair made me sit much more upright and this felt quite strange at first. Over time I did get used to this and I am noticing some changes in my sciatica. I still get problems when I sit for too long but it definitely helps to be able to move more frequently in the chair. I have also invested in some break reminding software which has also been very helpful.