ISO Office Chair Dimensions

The key dimensional requirements for office chairs in ISO standards mainly cover three major parts: the seat, the backrest, and the armrests, as detailed below:

1. Seat Dimensions

• Seat Height: This refers to the vertical distance from the front edge of the seat to the ground, a core parameter affecting sitting comfort. ISO standards typically specify that the minimum height of an adjustable seat should meet the user's need to have their feet flat on the ground (e.g., within the range of 400-500mm) to avoid blood circulation obstruction caused by leg suspension; the maximum height should be compatible with office desks of different heights (e.g., within the range of 450-550mm) to ensure that the desk height aligns with the user's forearms when their elbows are naturally bent.
• Seat Depth: This refers to the horizontal distance from the front edge of the seat to the backrest, directly affecting leg support. The standard recommends a seat depth of 400-480mm to accommodate users of different body types: insufficient depth can cause the back of the thighs to be suspended, increasing pressure on the buttocks; excessive depth may compress blood vessels and nerves behind the knees.
• Seat Width: This refers to the horizontal distance between the widest points on either side of the seat, which should meet the user's need for natural hip spread. ISO standards typically require a seat width of ≥380mm to ensure user stability and unrestricted movement.

2. Backrest Dimensions

• Backrest Height: This refers to the vertical distance from the top of the backrest to the seat, which should cover the main support area of the user's back. The standard recommends a backrest height of ≥480mm to support the area from the shoulder blades to the lumbar region, reducing fatigue from prolonged sitting; if equipped with a headrest, the top of the headrest should be adjustable to 100-150mm above the user's head to provide neck support.
• Backrest Width: This refers to the horizontal distance between the widest points on either side of the backrest, which should accommodate the user's shoulder width. ISO standards typically require a backrest width of ≥350mm to ensure unrestricted shoulder movement while avoiding insufficient lumbar support due to an overly wide backrest.

3. Armrest Dimensions

• Armrest Height: This refers to the vertical distance from the top of the armrest to the seat, which should match the user's elbow height. The standard recommends an adjustable range for armrest height of 200-300mm to support the user's natural arm placement and reduce shoulder and neck strain; fixed armrests should be designed based on the average height of the target user group.
• Armrest Spacing: This refers to the horizontal distance between the inner sides of the two armrests, which should accommodate the user's hip width. ISO standards typically require an armrest spacing of ≥480mm to prevent the user from colliding with the armrests when getting up or turning sideways.
• Armrest Depth: This refers to the horizontal distance from the front edge of the armrest to the backrest, which should accommodate the user's forearm length. The standard recommends an armrest depth of ≥150mm to support the user's forearms when they are naturally hanging down and fully placed on the armrests.

Significance of Testing: The above dimensional parameters are all verified through static testing methods to ensure that the office chair maintains structural stability during long-term use while considering the comfort and safety of users of different body types.