European Office Chair Dimensions

European office chair dimensions are primarily based on the EN 1335-1:2000 standard, covering 13 core parameters such as seat height, seat depth, and seat width. The specific requirements are as follows:

Seat height is the most fundamental dimension parameter of an office chair, typically set between 440 mm and 530 mm. This range is based on ergonomic principles, ensuring that when the user sits down, their feet can rest steadily on the ground while the pressure on the front of the thighs is moderate, preventing impaired leg blood circulation or sitting fatigue due to improper height.

Seat depth refers to the horizontal distance from the front edge of the seat to the backrest. It should ensure that there is a 2-3 finger-width gap between the back of the knee and the front edge of the seat when sitting. This design avoids pressure on the leg blood vessels and nerves while providing sufficient support area for the buttocks and thighs. If the seat depth is too short, it may cause the waist to hang in the air; if it is too long, it will press on the back of the knee, affecting comfort.

Seat width needs to accommodate the buttocks and thighs and leave an activity allowance of 5-10 cm. It is specifically measured as the maximum distance between the side edges of the seat surface, ensuring that the user can freely adjust their sitting posture and avoiding physical discomfort or muscle fatigue caused by insufficient space and long-term fixed postures.

Seat surface inclination is defined as the angle between the maximum inclined position of the seat surface and the horizontal plane, usually controlled between 0° and 5°. A slight backward tilt design helps disperse the pressure on the buttocks and guides the user to naturally straighten their waist, reducing the risk of lumbar lordosis.

The height of the back support point from the seat surface is a key parameter in backrest design. It refers to the vertical distance between the back support point S (located on the main axis) and the seat reference point A, with a standard specification of 220 mm. This height precisely supports the fourth to fifth lumbar vertebrae, effectively relieving waist pressure caused by prolonged sitting.

Total backrest height needs to cover the area from the lumbar vertebrae to the scapulae of the user, specifically the vertical distance between the upper and lower edges of the backrest. The height of the backrest from the seat surface refers to the vertical dimension from the seat reference point A to the upper edge of the backrest. Together, they ensure that the back receives comprehensive support, avoiding suspension or excessive pressure.

Backrest width is the maximum horizontal distance between the two side edges of the backrest. It should be designed according to the body types of the target population, usually matching the seat width with an appropriate allowance. Backrest horizontal radius is measured on the horizontal plane where the support point S is located, affecting the fit between the backrest and the back. Backrest tilt adjustment range refers to the maximum angle of the forward and backward positions of the backrest, with the standard allowing an adjustment of 15°-20° forward and backward to adapt to different work scenarios.

Armrest inner spacing is measured from the vertical extension lines on the inner sides of the two armrests. For irregularly shaped armrests, it should be measured on the plane 20 mm below the highest point to ensure that the shoulders are relaxed when the arms are placed naturally. The maximum radius of the base refers to the distance from the most protruding point of the lower bracket (including casters) to the rotation axis, affecting the stability of the chair. Stability dimensions are evaluated by testing the minimum distance between the tilt axis and the rotation axis. Chairs with casters need to be tested in the most unstable position to prevent the risk of tipping over.

These parameters are calculated by statistically analyzing the sitting posture data of people with different body types, taking into account both universality and adaptability to meet the needs of most users.