Measurement of width: folding multiple = total width of curtain after unfolding/window (or wall). Generally speaking, the folding multiple is 1.7-2.3 times. Too few multiples are unsightly, and too many multiples cannot be wasted. Usually 20% discount is appropriate. For linear windows, if curtains are to be installed on the whole wall, then: total width of curtains = width of whole wall ×2= length of guide rail × 2; If the curtain is only installed on some windows, then: total width of curtain = (clear width of window 15cm×2) × 2 = length of Roman rod or guide rail× 2. Total width of L-shaped curtain = (window long side size and window short side size) ×2 If Roman pole is used, the length of long pole = window long side size, and the length of short pole = window short side size; If a guide rail is used, the length of the long guide rail = the long side dimension of the window, and the length of the short guide rail = the short side dimension of the window. Height measurement: Compared with the measurement requirements of curtain height, the small size affects the appearance, and when the size is long, it will touch the ground and get dirty easily. Usually the bottom edge of the curtain is 2-3 cm from the ground. Traditional curtains are divided into woven curtains (hung with hooks) and perforated curtains (passed through holes with rods) according to the hanging methods. Ribbon curtain height =-2cm from the pulley on the guide rail to the ground (or -2cm from the pulley on the Roman pole); Height of perforated curtain =-2cm from Roman pole end to ground (height from ground); 2.5cm (the distance from the top of the curtain through the hole).