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.
The lower window casing that sits over a radiator or kitchen sink should act as the baseline for your curtains; the curtain's hem should just barely hide the trim. All other curtains -- regardless of window size -- should go to the floor with less than 1 inch to spare.
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.
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. But the reality is that various decorating styles use different curtain lengths.
The proper position is ½ inch above the floor for free hanging curtains. This distance allows for mopping and cleaning while creating the illusion that the curtain touches the floor. A popular hem finish for silk or lined curtains is called a trouser kick.
Hanging long drapes on a short window is one of the easiest ways to increase the importance of the window and bring it into proportion to the room. Short drapes on a short window call attention to the size of the window and reduce the significance of the room, window and drapery style.
Like most other rooms, curtains should extend to the floor (give or take an inch). In the bedroom, curtains should only be short when something would interfere with their ability to reach the floor. For example, the headboard of a bed or a radiator placed under the window.
For the drop you should measure from the top of the pole down to your chosen end point. The length is a matter of taste, so just keep measuring downwards until you've reached the point you want the curtains to end.
If you have the space between the top of your window frame and the ceiling or crown molding, though, you should hang the rod over the window. I like to go 3 to 5 inches down from the ceiling. Doing this visually extends the length of your wall, making your ceiling look higher.
If you are interested in stationary panels, you will want your curtains to be long enough to lightly brush the floor, but not so long that they bunch up in a pile. A good rule of thumb is for your curtains to break anywhere from a ¼” to ½” from the floor, similar to a break in pant legs on your shoe.
Floor-length curtains work best with radiators under the windows, but closing them means they'll block the heat generated by the radiator. Generally, pairing up floor-length curtains with other window coverings can do the trick.
Sill Length
These are the shortest of the standard curtain lengths, which makes them a good opportunity to have some fun with pattern or color. Since they take up less visual space, you won't get tired of a bold choice.
Making Your Room Look Larger or Smaller with Curtains
High-hanging curtains with long vertical stripes create the illusion of height, which is excellent for low ceilings. However, short curtains and horizontal stripes shorten your wall height and make the room appear smaller.
Short curtains. Short curtains and drapes are not ideal, and most often you don't want curtains that hang more than an inch above the ground. Too short curtains can not only look outdated, but they can also sometimes make the ceiling look lower.
One idea is to use a floor-length curtain to make short windows look taller. Hang them on stylish curtain rods installed at least 5 inches above the window frame. If your window is both short and wide, a medium-weight fabric is a better choice.
Curtains can catch fire from electric radiators if the radiator is close to a curtain made of flammable material. Water radiators usually don't get hot enough to cause curtains to catch fire, but the radiator could still burn any fragile materials nearby.
Additionally, thick curtains hanging over a rad may actually hinder heat from circulating evenly around your room and could cause you to turn the heat up to compensate. Increased use of energy would increase your heating bills. Decorative hanging drapes should also be kept well clear of radiators.
Any type of heater can start a fire under the right conditions, but fires started by curtains most often occur with electric baseboard heaters due largely to the way the heaters work. These heaters rely on the room's natural airflow to push the heat they generate into the room.
As a general rule of thumb, curtain width should be two to two-and-a-half times the width of the window. Curtains are typically sold as pairs, but you may need to double up depending on the size of your window.
For curtains that are way too long, you may have a lot of excess fabric left. You can trim this extra material at the end, but if you don't want to cut the curtains, make 2 or 3 folds so the excess material is tucked in neatly.
Do use curtains that reach the floor. Your curtains should either be 1/2” above the floor, kiss the floor, or puddle on the floor. For 8' ceilings, I recommend standard 96” curtains which you can then adjust up and down or hem up the bottom if needed.