You want to offer or make a custom chair. But as it is a surprise it is tricky to take the measurements of the person. In this case you can use the table below.
However, if you have the opportunity we will tell you below in this article how to measure the height and depth of the seat, as well as the height of the backrest.
Table of the average dimensions of a custom-made seat based on the height (in cm)
The following data correspond to an average measurement taken on a horizontal seat without a cushion. They are given in cm
. SH stands for seat height
. SD stands for seat depth
– SB stands for shoulder hieght backrest
. HB stands for high backrest including headrest
Warning: these are averages.
Indeed, data collected on 358 people (TU Delft 2020) actually show significant differences from person to person.
For example for a person of 180 euros/- 1 cm one of the 358 individuals measured needs a seat of 45 cm in height, But another individual of the same size needs a seat of 53 cm in height.
The discrepancies are also significant in terms of the depth of the
seatIn effect on this graph we have the size in abscisse and the seating slayer in order (sample of 358 people of the Delft TU). If the seat depth was proportional to the size the dots would draw a perfect straight: but the dot cloud draws an ellipse (for the statistics pros the correlation index is only 0.678).
How to measure the depth of a seat
Sit the person on a fairly deep horizontal surface and ask them to stand upright. Take a block (in blue on the drawing below) and lay it against the lower back.
1. Measure the distance between this block and the hollow at the back of the knee
.2. Remove about 4 cm to measure the seat depth of the chair.
Indeed it is important that the seat is not too long. Otherwise it comes in support against the hollow poplity and slows the venous return. Or the person slides forward more easily and adopts a bad posture for the back.
How to measure the height of a seat
Sit the person on a flat surface with their feet slightly in the air.
1. Shoe the person with slippers or shoes usually worn in the chair.
2. Add pounds or blocks under the feet until the front of the thigh is in contact with the flat surface. It is difficult to pass the hand between the thigh and the seat.
3. All that remains is to measure the distance from the underside of the heel to the seat
Measuring the height of the backrest
The seated person measures the distance between the seat and the shoulder blades for a medium back or the distance between the seat and the back part of the skull for a headrest back.