How to Measure for Blinds for Angled Windows

Tips Before You Get Started

  • Shop American Blinds for angled windows—choose from angle top or bottom cellular shades
  • Use a steel tape measure for the most accurate measurements on your angled windows
  • If you're considering an Inside Mount, make sure your window has enough depth to accommodate it
  • Always measure width (left to right) first and height (top to bottom) second
  • Record all measurements to the closest 1/8", making sure to clearly identify which is your height and which is your width—it is very common to get them mixed up

Determine Inside Mount or Outside Mount

  • Angled blinds or shades that are inside mounted will be cut to hang entirely within the window
    • We recommend inside mount whenever possible
    • Neat, streamlined look
    • Usually best for energy efficiency
  • Angled blinds or shades that are outside mounted will hang outside your angled window opening, overlapping the edges
    • We recommend outside mount for out-of-square windows, and for windows with minimal mounting depth or obstructions within the frame
    • Minimizes light gaps, giving you better light control and privacy

Diagram of how to measure for blinds for angled windows - angle top and angle bottom windows

Measuring for Inside Mount

Note: Inside-mounted angled blinds and shades will have a small deduction automatically applied by the manufacturer, to ensure proper fit.

Width

  • Measure at the depth within the frame where you'll install your brackets
  • Measure width at the top, center and bottom of the rectangular portion of your window opening; you will not take any measurements from the angled portion for this step
  • Record the smallest measurement (to the closest 1/8") as your Width

Height (Tall Side)

  • For angle-top windows: Measure the height of the "tall side" of the window opening, from the bottom edge to the top corner of the angled portion
  • For angle-bottom windows: Measure the height of the "tall side" from the top edge to the bottom corner of the angled portion
  • Record the measurement (to the closest 1/8") as your Height

Short Side Height

  • For angle-top windows: Measure the height of the "short side" of the window opening, from the bottom edge to where the angle starts
  • For angle-bottom windows: Measure the height of the "short side" from the top edge to where the angle starts
  • Record the measurement (to the closest 1/8") as your Short Side Height

Angle Length

  • For angle-top windows: Measure the length of the angled line, from where the angled portion of the window starts to its top corner
  • For angle-bottom windows: Measure the length of the angled line, from where the angled portion of the window starts to its bottom corner
  • Record the measurement (to the closest 1/8") as your Angle Length

Measuring for Outside Mount

Note: Outside-mounted angled blinds and shades will have no deductions taken at the factory. They will be made according to your exact measurements.

Width

  • Measure the area you want to cover, from left to right, in only the non-angled section of the window
  • Make sure your measurement overlaps the window opening by at least 2" on both sides
  • Record this measurement as your Width

Height (Tall Side)

  • For angle-top windows: Measure from the top corner of the "tall side" of your shade to the bottom of the window opening
  • For angle-bottom windows: Measure from the bottom corner of the "tall side" of your shade to the top of the window opening
  • Add the amount you want your shade to overlap (we recommend at least 2" on each side)
  • Record this measurement as your Height

Short Side Height

  • For angle-top windows: Measure from the top of the "short side" of your window (where the angle starts) to the bottom of the window opening
  • For angle-bottom windows: Measure from the top of the window opening to the bottom of the "short side" of the window (where the angle starts)
  • Add the amount you want your shade to overlap (we recommend at least 2" on each side)
  • Record this measurement as your Short Side Height

Angle Length

  • Measure the length of the angled side of your window and record this measurement as your Angle Length