The general rule is to hang the curtain rod at least 4-6 inches above the window frame, when there is at least 12 inches of space between the frame and ceiling. source: BHG. Your ceiling height is the first factor you should consider when deciding how high to hang your curtains.
http://www.houseontheway.com/high-curtains-hung/
Your ceiling height is the first factor you should consider when deciding how high to hang your curtains. If you have tall or cathedral ceilings, you should definitely hang them a minimum of 4-6 inches above the window frame. Obviously, if you have 20 foot ceilings, you do not want to hang them that high!
http://www.houseontheway.com/high-curtains-hung/
source: BHG. Your ceiling height is the first factor you should consider when deciding how high to hang your curtains. If you have tall or cathedral ceilings, you should definitely hang them a minimum of 4-6 inches above the window frame.
http://www.houseontheway.com/high-curtains-hung/
Measure 3 inches out to the side of each window frame, level with the top. You can hang curtains as wide as you want, but 3 inches out is standard. Mark the spot to the left of your window frame with a pencil or chalk. Next, measure straight up from the chalk mark and mark the spot you want your curtain rod to go.
http://homeguides.sfgate.com/hang-curtains-above-window-58254.html
Tip #1: Hang the Window Treatment High. Hang the window treatment high to give the illusion of height; this is the most important rule when hanging a curtain. The pole or valance should be hung a minimum of 4 inches and a maximum of 12 inches above the top of the window in most cases.
http://www.networx.com/article/8-really-good-tips-for-hanging-curtains
If you have tall or cathedral ceilings, you should definitely hang them a minimum of 4-6 inches above the window frame. Obviously, if you have 20 foot ceilings, you do not want to hang them that high! But you also do not want to have tall ceilings and have curtains that look small and diminished in the space.
http://www.houseontheway.com/high-curtains-hung/
The typical height for hanging drapery on a window that has more than 12 inches of space between the top of the window and the ceiling is about 4 to 6 inches above the window trim. If there is not at least 12 inches of space, hanging the curtains at window level may highlight the limited space.
http://homeguides.sfgate.com/hanging-curtains-ceiling-vs-window-56685.html
For example, if the height from the floor to the top of your window frame is 78 inches by 84-inch curtains and hang the brackets of the rod as less than 6 inches above the window frame.
http://www.bhg.com/videos/m/76359884/how-to-hang-curtains.htm
I cannot decide on window treatments, so am going to hang simple white sheers (Pottery Barn White Voile) on these windows. If I order in 84 length, the top of the curtain is just an inch above the top frame of the window. The next height is 96, but that's 12 inches above the top frame of the window.
http://www.houzz.com/discussions/697211/how-high-to-hang-curtains
Dress your windows right with these tips and tricks on how to hang curtains. Here's what you'll need to hang basic curtain panels; brackets in the rod, screws, a tape measure, a level, a screwdriver, a pencil and paper. If your drapes are heavy, you'll also need wall anchors to support the extra weight.
http://www.bhg.com/videos/m/76359884/how-to-hang-curtains.htm
how high above the window should drapes be hang
The window drapes should be hang above 4 to 6 inches.  