How to Measure for Roller Shades

measure for roller shades

Light control, privacy, adjustability and easy operation, roller shades obviously can offer numerous advantages. Moreover, they take up less space than regular curtain, which can fit nicely for small studio apartment or minimalist interior style. With free stop cordless design, roller shades are also safe to be used in public spaces like offices, hospital rooms or educational institutions.


Some customers may still be hesitating and worrying about whether the size of roller shades can match their windows or not. This blog is going to guide you how to measure for roller shades step by step with graphic explanation.

Choose Between Inside Mount and Outside Mount

Before all the measurement starts, it is necessary to make decision of where you are going to mount and install blind. Mounting on walls or within the window frame can satisfy different purposes. Now we are introducing the difference between inside and outside mount, then explaining each of their features. 

The Definition of Inside Mount

First of all, inside mount for roller shades means the blind headrail and valance will be mounted within the ceiling of window frame. Inside mounting roller shades provide a much clean and modern look, because they fit right in without having extra fabric outside of the casing. If you would like to layer different kinds of window treatments, inside mount will be a better solution since the roller shades will be positioned beneath all the other curtains.


One of the weak points of inside mount is the light leak problem. Another one is it will block the top section of the window even when the shades are fully opened. 

inside and outside mount valance position

The Definition of Outside Mount

When the headrail is mounted on the wall above the window frame or on the molding, this is what we call “outside mount”. The advantage of having outside mount is it can cover wider and larger area than having inside mount. It fills in the gap between the shade fabric and window frame to block out more light and is suitable for a space where you need complete darkness. Another merit of outside mount is that roller shade won’t cover the window when it is rolled up.

Required Tools for Measurement

  • Steel Measuring Tape
  • Paper
  • Pencil
  • Step Ladder (if needed) 
Tools for Measurement

    How to Measure for Inside Mount Roller Shades

    The measurement methods of inside and outside mount are quite dissimilar. GoDear Design team is going to illustrate each estimating process and helpful tips to avoid any possible misunderstanding.

    1. Window Frame Measuring Spots

    Measuring three different spots from the left to right, top to bottom. For inside mount, record the narrowest width and the shortest height that you have measured. 

    measuring spots from left to right

    measuring spots top to bottom

    When you have more than a window, even if they look alike, please don’t assume they have the same size. We recommend to precisely sizing each of the windows individually. Use a steel measuring tape for much more accurate measurement result.

    2. Knowing the Depth of the Window Frame

    When choosing inside mount, there is one more significant point to take consideration at the beginning. Make sure to measure the depth of inside frame first! This step is to check if the mounting requirements can correspond to the product you are going to order.

    Assuring the frame depth is more than 3 inches, which is for the headrail depth of the roller shades. Please be aware of the specification of the valance and bracket as well.

    inside mount window frame depth

    specification of the valance and bracket

    How to Measure for Outside Mount Roller Shades

    Outside mount is to install the bracket and the valance outside the window frame, usually on the wall or the header casing above the window. Here are the measurement steps:

    1. Measuring the Width

    Measure width of the area you are planning to cover. To block out more light, we recommend to add 2-3 mores inches on both side of the window frame.

    measuring width for outside mount

    2. Measuring the Height

    Measure the height which matches the position of windowsill. The maximum length of our roller shades is 72 inches, and they can fit most size of the half windows. For a full coverage, we suggest to installing on window height that is less than 65 inches.

    3. Reserving the Length

    Check the length between the edge of the frame and the spot on the wall that you are going to mount the hardware is higher than 3.5 inches, this is to ensure leaving enough space for the bracket and valance.


    If there is molding surrounding the windows or doors, add spacers if needed. Considering the bracket size and depth as well. 

    leaving enough space for outside mount hardware

    Headrail and Shade Fabric Size Chart

    Last but not least, please do pay attention to the corresponding size of the headrail and fabric. Fabric width is 2 inches shorter than the headrail (1 inch shorter on each side).


    When having inside mount, there will be 1 inch of space between the shade and the frame, light will penetrate through the gap.

    Fabric width is 2 inches shorter than the headrail

    Check the roller shades size chart below before making the decision.

    headrail and fabric width size chart

    Roller shades measurement is quite simple once you have learned the tips. Carefully amount and record the spots which we have pointed out, then you will have a smooth process when installing the shades! 

    Want to know more? 

    How to Install Roller Shades Properly?
    Are Window Valances Dated and Out of Style
    Beginner's Guide to Cordless Roller Shades

    Interested in our design concept? Following us on Instagram, Facebook, Twitter, and Pinterest!