Common lengths of standard draperies are 120 inches, 108 inches, 95 inches, 84 inches, 63 inches, 36 inches and 24 inches. The standard drapery panel width usually corresponds with the fabric bolt width used by the manufacturer. Common widths of standard tier curtains are 58 inches and 60 inches.
The common lengths for standard draperies for windows reach up to the top of the windowsill or just below it in the case of standard-sized windows. Some lengths reach halfway between the windowsill and the floor, whereas others reach to the floor.
If the window is of a length that falls within the range of the standard drapery lengths, then standard curtains that are slightly longer or shorter can be chosen to achieve the desired look. Alternatively, the position of the curtain rod can be altered to make up for the difference between the window length and standard drapery length.
To achieve a look of fullness, multiple panels of a curtain of a standard width may be used. For example, for a single window two panels of standard width are required. Accordingly, for a double window four standard-width panels are needed. Normally, the curtain width used is 1 1/2 to two times the width of the window.