For example on a 54 inch wide window you could extend your curtain rods up to 9 inches on each side 54 divided by three equals 18 so your rod can be up to 72 inches long.
Curtain rod above window trim.
In general windows with plenty of wall space on either side can afford a longer rod and larger finials.
Hanging curtain rods high above the window frame adds height to the wall and works best with long panels or drapes.
For cathedral ceilings leave approximately four to six inches above the window trim as a guideline.
When installing curtain rods hang the rod so that it extends at least 3 or 4 inches beyond the window on each side which allows your curtains to overlap both the window and the wall to prevent light from leaking in around the window s edges.
Mark with chalk or a pencil.
A rule of thumb from architectural digest is that curtains should be hung between 4 to 6 inches above the window frame so install your curtain rod accordingly.
See in the photo below how the rod keeps going well past where the window stops.
You may need to adjust the height of the pole for different curtain hanging styles.
Don t scrimp on length.
If that s the case i recommend hanging the rod about two feet above the window.
To find your ideal placement measure down from the ceiling to the top of the trim at the left corner of your window.
No matter what the ceiling height the minimum distance from the top of the window casing to the curtain rod is two inches.
When you hang the curtain rod high it will make the window appear taller.
Wall mounted rods are usually installed four inches above the window.
But for the rest of us.
Your curtains may hang from the pole using a sleeve rings or eyelets.
This applies if there are more than 12 inches between the window trim and ceiling.
The higher the rod the closer to god 2 extend your curtain rod so that it s at least 7 10 past the edge of the window.