How to Measure Bay Windows for Blinds

A bay window is at least three adjacent windows, with the outermost windows protruding out on an angle. A large bay window can make your space feel much brighter and allow more light in the room. Although bay windows can be elegant, window treatments are needed to ensure privacy but still allow for a picturesque view when you want it. Fitting or measuring window blinds to a bay window can take a little effort.

Bay windows can be a challenge to measure.
  1. Choose a window shade to determine the depth of the blind, which will be provided by the manufacturer. Different blinds have varying depths and will make a difference how the blinds hangs on the bay window.

  2. Figure out the intersecting points of each separate window to calculate the width of each blind.

  3. Cut two pieces of cardboard similar to the thickness of the window blinds and about 12 inches long. Place the cardboard so the front edges slightly touch at the meeting points like the blinds would. Draw a line with a pen on the edge of the cardboard where the pieces meet. Repeat this step for each intersecting point.

  4. Measure each bay window blind. The left window blind measurement is the meeting point marked on the window frame. The measurement should be the same distance from the left side of the window as the intersecting point. Repeat this method for the right blinds, and use the intersecting point on that side. Figure out the measurements for the center window by measuring the distance from the left and right intersecting point.

  5. Add 2 inches to the height to account for brackets. Measure the exact width of the windows for inside mounts. Outside-mounted blinds should rest just outside the window frame. Convert measurements to the nearest 1/8 inch.