If the average height of China people is about 1.7m, and the furniture size is designed according to the human body's freedom in space, the height of the chair surface from the ground is about 45cm[ the height of the front leg of the chair is 43cm, the thickness of the chair panel is 2cm], the height of the chair backrest [also called the back leg of the chair] is about 86cm, and the height of the stool surface should be 45cm [the wooden leg is 43cm plus the panel is 2cm] to 50cm [the wooden leg is 40cm].