Seat surface:
The physical dimension of a seat plate must fit the dimensions f the user‟s body. For this, the postural variations of using the seat depending on various contextual uses, involving the static as well as the dynamic dimensional variations have to be incorporated.

Seat wide:
Normally the hip dimension may be used for a static fit. But depending on the various sitting postures of off-center and, sitting and, the mid-thigh. Roughly, it could be said that the minimum mid-way seat width should never be less than 400mm.

Seat depth:
A narrow sectional curvature restricts free buttock and thigh movement leading to discomfort. Roughly the effective seat depth should be around 400mm for general purpose.

Seat height:
The foot must be securely place on the floor or on the foot rest in a seating position and this is possible only when the height of the seat matches the length of the foot rest and the popliteal distance. The centre height of a seat for those using footwear, may be around 435mm with an adjustability rang for lower and higher value of 400-470mm. people of lower height using shoe, etc., can make up the height and taller people can sit with somewhat extended leg, but this depends on contextual variation.