How to Measure Correctly for Window Blinds

Window blinds can enhance a window treatment by providing privacy and light filtering. Blinds are very versatile: When you don't want to see the blind, they can be rolled up and hidden beneath a decorative valance. They come in various lengths and widths to fit almost any size window and can be installed either inside the window frame or on the wall surrounding the window. Either way, proper installation depends on good measurements.

A proper fit on your window blinds depends on good measurements.
  1. Measure the depth of the window frame to determine if the blinds can be installed inside the window frame. The blinds need to be able to fit completely inside the frame for this type on installation. For example, a mini blind that is 2 inches thick will need a window frame that is at least 3 inches deep. If the window is not deep enough, mount the blinds to the wall surrounding the window.
  2. Measure the width of the window to determine the width of blind you can install. Measure the top, bottom and middle of the window to make sure the width is the same -- use the largest measurement if there is any variance in the window width. If the blind will be installed within the window frame, use the exact measurement to purchase your blinds. If mounting outside the window, add as many inches as you desire to cover the window frame.
  3. Measure the height of the window at both the left and right sides of the window to determine the length of the window blinds. Use the longest measurement if there is any variance.

Things You Will Need

  • Carpenter's measuring tape


  • Write down your measurements to take to the store so you remember the proper length and width for the blinds.


  • Do not use a plastic measuring tape, such as those used to measure fabric for clothes. These tapes can stretch over time. Use a metal carpenter's tape measure instead.
  • Do not use a yard stick or ruler to measure your window. It is too easy to make mistakes when measuring distances longer than your measuring tool.

Photo Credits

  • rainbow blind background image by Stephen Orsillo from Fotolia.com