While fashion once dictated a “flood level” bottom line for curtains—one that hung just past the window sill, short enough that it would not get wet in a flood—today, style calls for curtains to either hang down to within ½-inch of the floor or even puddle slightly.
A rule of thumb (from Architectural Digest) is that curtains should be hung between four to six inches above the window frame, so install your curtain rod accordingly. When you hang the curtain rod high, it will make the window appear taller.
A common rule for displaying curtains properly says the curtains finished width should be at least 2 times the width of your window (if not more - sheers can be 3 times the window width) to achieve a look of proper fullness.
The answer to this question is important because it can affect the way we do our decorations. Yes, curtains should be long enough to touch the floor. With a few exceptions, the longer the curtains are the more stylish and elegant it will look. This is why most standard ready-made curtains are lengthy.
How Wide Should Curtains Be? To ensure that panels look ample and drapey when closed, they should have a combined width that is 2 to 2½ times the width of the window. Exceptions: If you're hanging curtains just to frame a window and don't intend to shut them, you can round down to 1½ times the width.
The material should barely touch the floor or hover half an inch above. Use this approach for café curtains, too, short panels covering only the lower portion of a window, hitting the sill, which works well in kitchens and bathrooms, where long drapes or curtains aren't practical.
Below the sill
Typically the most popular choice for short curtains, this drop overlaps the sill to help block out external light and draughts and even has the opportunity to go wider than the window to ensure maximum light when the curtains are open without looking unbalanced.
The higher the curtain rod, the taller the window will appear, so fix your curtain rod closer to the ceiling than the top of your window, if you can. One rule of thumb is that they should sit 4-6 inches above the window frame.
"Extending your draperies from floor to ceiling and from wall to wall surrounding your window makes them appear bigger," explains Francesco Bilotto.
Hanging your curtains at ceiling level maximizes the light that shines through your window and it makes the room feel larger because the walls look taller. This works well in a small space, but may not be ideal in a room that is already too large.
For example, for a 60-inch window with two curtain panels, add 24 inches to 60 inches (window width) and divide by 2 (number of panels) to get 42 inches. The two panels ordered each need to be at least 42 inches wide.
To get the measurements, measure the width of the rod from left to right. For instance, if your window measures 72” wide, you will need curtains that will give a maximum width of 144” (window width x 2 = 144”.)
Keep in mind that the width measurement is flat. If you hang a 48-inch panel on a 48-inch window, there will be no fullness or draping. According to Curtainshop.com, finished curtains should be twice the width of the window, so if your window is 36 inches wide, you need panels that are at least 72 inches across.
So should curtains touch the floor? The short answer is yes... usually. But when making any decision about your window treatments, whether they're drapes, blinds, or shades, it's important to consider every aspect of style and function so you can choose the best option for your windows and your home.