Curtain measurements are always written with the width first and then the length. For example, a panel that is 46″ x 54″ is 46 inches wide and 54 inches long. Don't buy your curtains just so they're big enough to cover a window.
When we list or write curtain measurements, the width always comes before the drop. Ready-made curtains are available in three standard widths: 112 cm (44 inches), 167 cm (66 inches) or 228 cm (90 inches). You should choose the width that most closely matches the size of your track or pole.
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”.)
For a 60 inch (152.4cm) window, you need curtains with a finished width at least 1.5 times that, but better are those with twice that width and even three times the width for sheers. Therefore, for a 60 inch window, you need two panels of 60 inches each for twice the width and a luxurious gather.
How wide should curtains be? To ensure that curtain panels look ample when closed, they should have a combined width that is 2 to 2.5 times the width of the window/rod. That means if you are ordering Grommet style or Rod-pocket style, the total drapery width should be at least 2 times the window/rod widths.
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.
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.
How Wide Should Curtains Be For A 72-Inch Window? Let's say you want standard, thick curtains to cover your 72-inch window. You'll want to look for curtains that measure between 144 and 180 inches wide.
In the US, the standard curtain width would be 54”. But generally, it ranges from 50-58”. Some curtain manufacturers even go for as long as 108”. Again, knowing the curtain width is as essential as the length because you have to align it with standard curtain sizes.
Example: If your window measures 36″ wide (window width x 2 = 72″), you need curtains that will give a minimum width of 72″ or 2 panels for that window. In this case 2 panels will give about 100″ to 120″ of width which will look nice and full.
For example, if the window is 100 inches wide, the curtains should be made to 125 inches wide in order for them to hang off the window when in the open position. For an inside-mount curtain, measure from one edge inside the frame to the inside edge on the opposite side.
First calculate the width you need. Measure the full width of the curtain pole or track not the window, excluding any fixtures or finials on the ends. If your curtains are pencil pleat, tab top or eyelet, double this width measurement to account for the way the curtains will be 'gathered' at the top.
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.
As a general rule, drapes will be open during the day, so make sure the curtain rod extends at least four inches on each side of the window's inside frame. To create the illusion of a wider window, extend the rod up to 10 inches beyond the window's frame.
It is normal for curtains to touch the floor. Some styles even need more length to produce a certain look. Using any of the curtain length styles is fine as long as it enhances the beauty of your home.
The rule of thumb is to go 8″-12″ wider than your window.
For a 120-inch window, how wide should curtains be? Depending on the weight of the fabric and how much you want the curtains to be. At least a width and a half is what I would recommend. 180 inches is the width of each curtain.
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.
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.
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.
For a 9 foot ceiling, pick 96-inch curtains. Typically, your curtain rod is hung about a foot from the ceiling. 96 inches covers the distance between the floor up to one foot from the ceiling.
Sill-length curtains stop at the bottom of your window, or a few centimetres further down. They can be the best style for window seats and large window sills, or for rooms where the radiator is situated directly underneath the window. They are best suited to informal, country-style homes and children's bedrooms.
For a typical window without architraves, we recommend poles/tracks overhang the width of the window by not less than 15cm (6") each side (excluding finials). Mark the pole/track and check your measurements again.