The length of your curtains can make a big difference for the overall look. Floor to ceiling curtains, for example, create an elegant effect.
If you want a few different options, Kerrie Kelly of Kelly Design Lab in Sacramento, California, recommends following these tips:
1. First, you'll need to measure your window to estimate the amount of fabric your need. The best approach is to work directly from the window measurement rather than from the hardware. You will get the most accurate results by using a retractable steel tape measure.
2. For a treatment mounted inside the window, measure the width of the opening and the length. If your treatment will hang outside the window opening, as most do, measure the area to be covered to the left and right of the opening and the distance above the opening. The top of the treatment is usually even with the top of the trim board, but you may also mount a treatment just below the ceiling, at the bottom of the crown molding or halfway between the ceiling and the window opening.
3. The distance below the opening varies, depending on the treatment style. Some treatments end at the windowsill. Apron-length treatments usually end 4 inches below the opening. Floor-length treatments usually end one-quarter to 1 inch from the floor, but if you want the panels to puddle on the floor, allow for several extra inches when measuring.
4. If you want a fuller curtain, purchase panels double the width of your windows. Fuller panels always provide more drama. The higher the ceiling, the fuller the drape body should be -- it is all a matter of proportion.