The standard dining chair size ranges from 16 to 20 inches wide, with a seat height of 18 to 20 inches. Chair depth is typically around 18 to 22 inches, providing comfortable seating without overwhelming the space. Backrests vary, often between 30 to 40 inches in height, offering adequate support. Armchairs may be slightly wider (20 to 24 inches) due to the arms. While these measurements fit most tables, always consider your table’s dimensions and available space to ensure an appropriate fit for your dining area.