Sofas are generally measured in width, height, and depth. The width is the distance between the two farthest points on the sofa, while the height is the distance from the ground to the highest point on the sofa. Depth is measured from the front of the sofa to the back. Traditional sofas are between 80 and 90 inches wide, 36 to 40 inches high, and 38 to 42 inches deep.