How to Measure and Cut Roller Shades for French Doors


I have four complete sets of french doors in my home, one being my front door.  While they are beautiful, the last thing I need in the morning is sunlight hitting my eyes from every angle.  I’ve spent approximately $1K hanging drapes, and even though I love them, sometimes I want to change the look of the house without spending as much as I did on the drapes. I love doing new projects to make my house more beautiful.  Even something like installing roller shades or cellular shades becomes akin to art; the good hormones released when doing art are similar to the hormones released when you complete a project and are see the beauty of it.

According to homeadvisor.com, it can cost anywhere from $217-$1,152 to install new shades.  This depends on whether you have someone else do the measuring and installation for you.  It also depends on the material you are using (vinyl or fabric) and whether you are purchasing custom fit shades or store-bought shades you will size down yourself.  Doing the latter is fairly easy and will knock the price down quite a bit.  All you need for measuring and installation are the following:

  • Measuring tape
  • Pencil
  • Step Ladder
  • Drill with bits – 3/32″, 1/4″
  • Screwdriver
  • Roller kit
  • Straight edge that is approximately the length of the roller shade
  • Hacksaw

Coverage Options

First you need to decide how you want to mount your shades.  Do you want to cover the entire door or just the glass panel?  My French doors cover a large area, but there are panels around the doors that also let light in.

When I first moved into this house, the previous owners had cellular shades covering the entire expanse of door and panels.  The shade was huge and cumbersome to roll up and down because they were so huge.  Personally I think that even though it seems like a pain now to mount a separate roller shade to each glass panel, in the long run it will be easier functionality wise.  I have little kids as well, and truth be told, they break everything they touch.  If they broke one of the panels, it would not break my bank to go out and get another.  I would not have to replace the entire panel.

If you do not have little kids, and you will not be opening and closing these shades very often, you can opt for the more dramatic look of covering a big area with one shade.  If you are willing to spend a little more, you can choose a motorized option, which we will discuss later on.

Mounting Options

Next you need to decide how you want your shades to be mounted.  There are three kinds of mounting options: inside mount, outside mount and ceiling mount.

Inside Mount

This can be used if you are mounting each panel around the doors, like I would be.  You will mount the brackets inside the frame of the panel and your shade would be measured to fit exactly inside the frame of the panel.  One thing to note about inside mounted window treatments is that it allows the beauty of any moldings you have around your windows.  When mounting from the inside, you have two options of how you want to mount them:

  • Standard Roll – This is the ‘normal’ way to mount roller shades, with the fabric rolling off the back, closer to the window.  Think toilet paper roll rolling away from you rather than towards you.  It may seem inconvenient because, you can see all the hardware, but being closer to the window allows it to cover more of the window. More coverage = More light filtering
  • Reverse Roll – The toilet paper comes off the top towards you.  Similarly, the shade comes off the roller from the front, blocking all hardware.  The reason for doing it this way I would say is purely cosmetic, because it doesn’t provide better coverage.
Outside Mount

This will be used on the door itself or if you decide to install a shade to cover the entire area that includes the door and glass panels around.  The reason this type of mounting has to be used on the door is because there is not enough depth of a frame to attach the brackets to.

Ceiling Mount

You mount wall coverings from the ceiling if you do not have adequate space within either part of the frame.  These need to be mounted from either the rafter beams (wood lengths that run from the wall plate to the apex or top point of the roof), studs (the upright support in the wall to which the drywall is attached) or joists (which are the horizontal framing length of wood that is used for support.  It runs parallel to the ceiling and floor).

Ceiling mounted coverings end up being quite costly, because you will have to purchase a shade to cover way more area than you bargained for (the area between the ceiling and the top of the first panel).  In addition, they will end up being a little more permanent.  Tell me truthfully, how often will you change or even clean something like this?  To me, ceiling mounted coverings should be used in places like galleries or the like.

Take your measurements

Before you start actually measuring, note the following:

  • Use only a steel tape measure for accuracy.
  • When measuring, label the width first then the height second.
  • When measuring, do not round up or down by inches.  Always round to the nearest 1/8″.
  • Measure Every. Single. Panel. Separately.  Always. Even if they look the same, they may differ ever so slightly.
Inside Mounted Measurements
  • First measure the depth of your frame, from the front of the frame to the glass.  Keep this number handy because you have to ensure it meets the requirements to do an inside mounted shade.  Before you purchase a roller shade, do your research! Check specs on the shade for their requirements for mounting.
  • Measure next the width of each window at the top only.  Again, and I have to keep repeating myself here, each window is its separate entity.  Do not measure for one and use that measurement for all, even if they look the same.  You will end up with less coverage on one and too much on another.
  • Measure the length of your window in three places: left, center and right.  Use the shortest measurement to the closest 1/8″.
  • Order that exact size.  ***The factory usually will make its own deduction to fit inside the opening for inside mounted shades.
  • If you are buying pre cut shades, make sure you add a 1/4″ to the width total for the mounting brackets.
Outside Mounted Measurements
  • First measure the width of the area you want to cover.  Usually it is recommended you go 2″ past the window on each side for better light filtering and privacy.  Then add 3″ to determine the bracket-to-bracket width.  For example, if your window is 36″ wide, add 2″ to each side (40″), then add 3″ for the bracket-to-bracket width (43″).  This would be your measurement.  ***The factory makes outside mounted shades exactly the size you give.  If you want the fabric to be wider, make sure you take that into account when giving measurements. 
  • Next measure the length you want your shade to be.  If you have a window sill above the window, it is recommended that your add 3″ to the top to allow for hardware placement.  If there is no window sill, a 2″ allowance is fine.  Measure as far down as you want your shade to go.
  • Order that exact size.

Cutting to Size

If you are going the route of saving money, you will probably end up purchasing your shades pre-sized, or listed as cut to width.  If this is your case, read on!

  • Unroll the entire roller shade.
  • Take out the plastic bar at the bottom of the shade. We will cut that later.
  • You already have your width measurement; using the steel measuring tape, measure the top from the shade plastic cap inward.  Make sure you don’t cut this part out (the plastic cap side with the pin).
  • Measure down the fabric of the shade in multiple places 2″ less than width measurement of the bar.
  • Take your straightedge and draw a line down so you know exactly where to cut.
  • Cut along that marked line with a very sharp scissors.  At the top you will have to unroll the fabric from the bar to cut the rest off.
  • Use a screwdriver and pop off the plastic end at the top of the side being removed.
  • Peel the fabric back from the tube/bar at the top that you need to cut to size.  Cut the rod at the top with a hacksaw.
  • Stick the fabric back into place and pop the cap back in.  Use a hammer or mallet if needed.

***Note – some brands of roller shades have tubing and material that you don’t need to cut.  Levolor makes one where the fabric peels off very easily and the casing at the top is one tube in another that can adjust to width.  If this more your speed, go for it!

After you going through these steps, you are finally ready for installation!

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