1. Assemble Your Tools:
Grab a pencil, paper and a metal measuring tape for taking window measurements. If you’re using a cordless drill to hang up your drapery rod, make sure your battery is fully charged. Decide on the type of aesthetic appeal that you are trying to achieve as well as the intended function of the window coverings and purchase your curtains and hardware accordingly. TIP! Be careful when using a fabric measuring tape as it can stretch or droop, leading to inaccurate measurements.
2. Choose Your Mounting Technique:
To determine how long your drapes should be, consider the mood you want to project in the room. To create a formal room, curtains should puddle on the floor (to achieve the ideal drape puddle, you should add 2-4″ of additional fabric to your length). Otherwise, fabric should hit the top of the floor. Fabric should always be long enough to cover the baseboard.
When preparing to hang drapes using an outside wall mount, make sure the hardware extends 3″ to 4″ beyond the outside of the window frame and 4″ to 6″ above the trim. To ensure minimum light gaps and maximum privacy, add 4″-5″ of fabric on both sides of the window. For narrow windows, additional fabric should be added to the sides of the window frame and fabric should cover the frame, exposing a small amount of glass.
If you are attaching hardware on the side of the windows to loop tie backs through, make sure your measurements are even on both sides of the window.
 Inside Mount Drapes |
 Outside Mount Drapes |
 Hanging Hardware |
- Inside Mounts:
Creates a sleek, modern appeal to windows. The inside mount technique is appropriate for applying Roman shades or if you want to keep molding in line of sight. Remember to keep all hardware within the frame. When measuring for an inside mount, begin with the width. Measure the window at 3 different points (top, middle, bottom) and use the narrowest figure for your final measurement. For determining the length, measure 3 different points and use the longest figure for your final measurement (unless you are hanging Roman shades, than use the shortest measurement.)
- Outside Wall Mounts:
A more traditional, classic method for mounting drapes, outside wall mounts are perfect for creating the illusion of larger windows or for draping a fuller, more-dramatic look with more fabric. If you have a really wide window, you can break up the space by hanging several panels across the window. Hang your drapes so they flow straight down, or tie them back in pairs to show a more formal window treatment.
3. Choose Your Drapery Rod Length:
When choosing rod length, measure from bracket to bracket. Remember, most rods are expandable, and while they are offered in standard sizing (10″, 12″, 14″) they may be cut to a custom size or joined together for a greater length.
For a room with low ceilings, you can add the illusion of height by placing the drapery rod closer to the ceiling. If you want a fuller, layered-look of fabric that creates a more dramatic window treatment, consider purchasing a double rod.TIP! Plan for fabric to be 2 to 4 times that of your window’s measurement for a rich, full look. Remember lightweight sheer fabrics create a lightweight treatment so you may want to purchase more fabric than usual, depending on your desired look.
the Original link
http://www.improvementscatalog.com/RoomForImprovements/how-to-measure-for-drapes