Tips on how to measure your windows:
Inside or Outside
Depending on your decorative needs, window coverings may be mounted inside or outside the window casing and may be with or without a valance. For accuracy, be sure to measure your windows carefully with a metal measuring tape.
is most common for standard windows. Measure the exact inside width and height
of the window opening between window jambs.
Outside mounting is used for shallow window casings, door mounts and custom looks. Measure the exact outside width and height from molding to molding. To overlap the window, we recommend you add 3" to your width and height measurements.