The starting point for any window treatment is your window. And regardless of which window treatment you’re going to use, be it curtain, drape, shade, or blind, you need to know how to measure your window.
Paper and pencil. You always want to write down the location as well as the measurements of the window that’s going to receive the window treatment. My bedroom window and my office window look exactly the same. But when it came to measurements, they were slightly different. To make sure the right shade got on the right window, I had my notes to keep them straight.
Measure the width of the window first, then the length. That way, you’ll be consistent. And this is the preferred sequence when ordering custom window treatments.
Metal tape measure. I use a 1 inch wide by 25 foot long metal tape measure. The numbers on it are large and easy to read. Cloth measuring tapes will stretch, throwing off your measurements. You’re going to need precise measurements to the closest 1/8 inch.
Measure all the windows, then double check all your measurements, just to be sure. This is especially important if you are ordering a custom window treatment.
Measuring the Window Rod Width
In the diagram, the curtain rod is centered at the top of the window, near the edge of the casing, with the curtain hardware attached to the window casing.
If you want the trim or molding around the window to show, attach the rod flush with the edges of the window panes.
You can also attach the rod above the window:
- Flush with the edges of the window casing. Attach the curtain hardware to the wall.
- Using any length rod you think is attractive. Attach the curtain hardware to the wall. (See photo.)
Window treatments such as blinds or shades do not use rods. In this case, you can:
- Use an interior measure, which means measuring inside the casing.
- Use an exterior measure, which means measuring outside the casing.
Measure the window in three places: top, middle, and bottom.
Final Width Measurement
- You final width measurement should include the length of the returns, if you are using the type of curtain rod shown in the diagram above.
- For center overlap, add 4 inches. (Not needed for one-way traverse rods.)
- Finials should not be included when measuring decorative rod width.
- If you want a fuller look, the final width of your curtain or drape should be about double the width of your window.
Measuring the Window Length
Sill length. This is for curtains that will touch the window sill. This is a common and practical length for kitchen windows.
Apron length: This allows your curtains to fall to the bottom of the apron below the sill. This length is also for kitchen and bedroom windows. It shows a bit more curtain fabric that the sill length. It’s a good length to use with tiebacks.
Short curtains, or those attached to rods on the window casing typically use these two lengths. These two lengths are often associated with a more casual, informal style.
Floor length. Longer lengths are typically associated with a more formal or dressy window treatment. Floor length is typically used for drapes that are attached to wall-mounted rods. This length should barely touch a tiled or wooden floor. For a carpet covered floor, you may want to clear the carpet by about an inch.
Another popular option is to let the drapes pool on the floor. This window treatment gives a plush, romantic look to the room. You should add inches to your length measurements depending on how much of the drape you want to pool at the bottom.
Type of Rod Impacts Measurement
The type of curtain rod you are using will affect the length measurement.
If you are using a standard curtain rod that will not be seen, measure from the top of the rod.
If you are going to hang your curtains from a decorative pole with rings, measure from the bottom of the rings you will be using. Remember that rings come in different sizes, so use the size of the actual rings you will be using.
With these measurement rules in mind, you should be able to easily order a ready-made or custom window treatment that will enhance your décor.
For more information about curtain and drape hardware, read Curtain Hooks and Rings.