Width: Measure the track (A) and
not the window. The track should usually extend 30cm (12")
beyond each side of your window to enable your curtains to be
pulled well back during the day. If a curtain overlap is
required, add (B) plus (C) for the total track width.
Length: There are three basic
lengths to choose from: sill length(D), below sill(E) and floor
length(F). Curtains should finish 1.3cm (1/2") above the
dill, 15cm (6") below the sill, or 2.5cm (1") from the floor.
Measure from the point where you wish the top of the curtain to be,
down to the appropriate point. The length measurement must
cover the total curtain length including the the chosen heading
type.