The first measurement needed to calculate how much fabric you will need is the width of your curtain rail or pole, or your pelmet width.
Rail Width for Pelmets
Please note: the pelmet width is the width of your pelmet rail or board including the length of the pelmet return to the wall.
Rail Width for Windows
If you have not yet fitted your rail or pole, measure the required width, taking into account the space needed for the curtains to be drawn back either side of the window. We recommend at least 15cm (6"). This measurement will increase for wider windows to allow the curtains to draw back away from the window. We recommend adding at least 15cm (6"), but it may be advisable to add as much as 20-30cm (9-12") for wider windows. Please see our guides to measuring for curtain poles and curtain tracks for further help.