Max. user weight
The highest weight that the chair is guaranteed to withstand with regular use — in other words,
the maximum weight of a seated person, allowing you to constantly use the product in normal mode without fear of unexpected breakdown. Note that many models are able to endure short-term excess weight without problems, however, anyway, it is not worth overloading the structure (and even more so doing it all the time): off-design loads will significantly increase its wear, and breakdown can occur at the most unexpected moment.
Back height
Chair back height; for models with a variable back height (see "Adjustments"), as a rule, the maximum value is indicated.
The back height is measured from the seat to the top edge. In essence, this is the height of support available to the back. In some situations, you can not pay much attention to this indicator - for example, if the chair is intended for visitors and the role of the back in it is purely symbolic. However, if you have to sit in a chair often and for a long time, this point should also be taken into account. Ideally, it's best to try a few chairs "live" and find out which backrest height is most comfortable for you. If this is not possible, it is worth deciding which area on the body the back should reach (to the shoulder blades, to the base of the neck, etc.) and measure at what height from the seat this area is in a sitting position. And if you need specific support for the back of the head, you should choose among models equipped with head restraints (see above).
Shoulder back width
The width of the back at the shoulders of the intended wearer.
In order to recline as much as possible on the back, this width should be no less than the actual width of the user's shoulders. At the same time, for more or less comfortable use, a smaller back size is also sufficient — approximately corresponding to the width of the back in the area of \u200b\u200bthe shoulders (between the outer edges of the shoulder blades). Well, anyway, this parameter is, on the one hand, secondary, and on the other, very subjective. This means that in most cases you can not pay much attention to it, however, if you have already decided to choose the furniture that is the most suitable in size, it is better not to measure your own back, but to test several chairs and determine the most convenient value by experience.
Seat size (WxD)
Dimensions of the seat installed in the chair in width and depth (from the back to the front edge). For models with variable depth (see "Adjustments"), the maximum value is taken into account when the seat is pushed forward to the stop.
Most modern chairs are designed for the average adult, so paying attention to size is primarily for people of a large, or, conversely, miniature physique. In width, the average is considered to be 45 – 55 cm, the narrowest models are up
to 40 cm wide, in the widest it can
exceed 60 cm. Similarly, a depth of less than 40 cm is considered small, up to 60 cm — medium, more than 60 cm — large.