Essential measurements for a new chair

Essential measurements for a new chair

These measurement guidelines are mainly for people wanting to purchase a high back or riser recliner chair. We recommend that measurement for more specialised seating or seating requiring a higher weight capacity be carried out by an Occupational therapist or Physiotherapist or experienced supplier.

It is advisable to try out a range of chairs before buying one because slight differences in the slope and angle of the backrest or the position and style of armrests can make a big difference to individual comfort.

Equipment Demonstration Centre in the UK have a permanent exhibition of products and equipment designed to enable independent living. The centres provide individuals with opportunities to view, and try, products and equipment and obtain information and advice from professional staff about equipment that may assist them.

Important dimensions

The internal dimensions of the chair - seat height, width and depth, and backrest height - need to suit the size of the user to ensure adequate support. It is also worth bearing in mind the overall dimensions of the chair if space is limited. If the chair is going to be reclined regularly, make sure that there is sufficient space behind the chair for the backrest to move.

Seat height The height of the seat can determine how easy it is to get in and out of the chair. A high seat will make it easier to stand up and sit down, particularly if you find it difficult to push up from the armrests or if you have any pain or weakness in your legs. However, if the seat is too high, your feet will not touch the floor and it may feel uncomfortable under your thighs. A seat that is too low will be more difficult to get out of and will direct pressure towards the pelvis rather than distributing it evenly along the thighs. As a general guide the seat height can be calculated by measuring the distance from the floor to the crease at the back of the knees. When seated, the hips and knees should be at right angles whilst your feet are flat on the floor

Most high seat chair manufacturers have a range of chairs with a seat height between 46 - 59 cm (18 - 23 in). For a person with a shorter leg length this could be too high but it would depend on how easy it is to compress the cushion. Some will make other heights to order. If you need a very high seat to make standing easier but need support for the feet when seated, try using a footstool but make sure you can push it out of the way easily before standing up. However you still need to ensure that your feet can touch the ground so you can independently get out of the chair.

Seat width. The seat should be wide enough to allow you to sit comfortably, but narrow enough to enable you to make use of the armrests. Ideally, it should be the width of your hips plus a couple of inches on either side.

Seat depth (front of seat to backrest) The seat needs to be deep enough to support the full length of the thighs. If the seat is too deep, you will have to lean back to provide support for the shoulders. This may cause you to slump in the chair and the cushion may rub behind your knees. A deep seat may also cause your bottom to slide forwards in the chair. If it is too shallow, your thighs will not be supported properly and after a while you may be uncomfortable. To calculate the correct depth, measure the distance from the back of the bottom, along the thighs to approximately 3 cm (1.5 in) behind the back of the knees. When seated you should be able to place two fingers together between the edge of the seat and the back of the knee. A greater depth should be allowed if you require additional back supports or cushions.

The back height for a chair is also important particularly if head support is required. The chair needs to be in proportion to a person's trunk height so that if a chair is providing head support it conforms to a person's dimensions.

The armrest height. For comfort the armrest should allow you to rest your arms without raising or dropping your shoulders and should support the full length of the forearm.

Advice last checked: 25 January 2019 Next check due: 25 January 2022

All advice is either supported by references (cited in the text) or is based upon peer reviewed professional opinion. Our advice is impartial and not influenced by sponsors or product suppliers listed on the site.
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