1 = Width, the distance from one side of the bag to the other side of the bag. Width is normally measured along the bottom of the bag. Handbags that change shape may be measured at the top and in the middle.
2 = Depth, the distance from the front of the bag to the back of the bag. Depth is normally measured along the bottom of the bag.
3 = Height, the distance from the bottom of the bag to the top of the bag. Handbags with slouchy or scoop designs at the top are measured from the bottom of the bag to the lowest point of the slouch/scoop.
4 = Drop, the distance from the center peak of the handle/shoulder strap to the center top side of the bag. Drop is normally measured along the underside of the handle/shoulder strap. Handbags with drops below 7" should be carried by the hand or worn on the arm. Handbags with drops of 7" or longer can be worn on the shoulder.
