How to Measure for Bay Window Curtain Panels

Place a stepladder at the leftmost side of the bay window so that you can easily access the wall space above the window frame.

Hold the end of the tape measure at the left edge of the bay or whatever point you want the outer edge of the curtain to be, and stretch the other end to the point where the first glass panel segment ends or where you want the other edge of the curtain to be. Write down the measurement and designate it as panel A. You may need another person to accomplish this, depending on the size of the window.

Reposition the stepladder to the center segment of the bay window and place the tape measure at the point where you stopped measuring previously. Stretch it to the right side of the center segment and write down this measurement, noting that it is panel B.

Reposition the stepladder once more in front of the right window segment. Measure from the point you stopped previously all the way to the right side of the glass or edge of the bay, and note the measurement. Mark this measurement as panel C.

Measure any additional window segments, if your bay window has more than three segments.

Place the end of the tape measure at the point above the bay window where you will install the curtain rod. Your options include the wall, the ceiling or even on the trim above the window. Measure down to approximately 1 inch above the floor to determine the proper length of your bay window curtains.