You may like the style your old bay window, but its condition may have deteriorated. It’s probably time to replace it with a modern bay window, but accurate measurements are vital when replacing windows. Learning how to measure a bay window takes only a few steps. You may want a partner to help hold the end of the tape measure.

How to Measure a Bay Window Steps

1. Begin by measuring the widths of the two windows forming the ends of the bay.
2. Place the tape measure tip on the seam between the casing trim and window frame.
3. Extend tape measure until it reaches the center of the adjoining window’s joint with the window that you’re measuring.
   1. Record the width measurement on paper.
4. Position the step ladder in a stable spot if you need help reaching the top of the window.
5. Hold the tip of the tape measure at the top seam where the casing trim meets the window frame.
6. Pull the tape measure to the bottom seam.
   1. Record the height on paper.
7. Repeat this measurement process for the window on the opposite end.
8. Take multiple height measurements across the bay window to ensure you have the correct height.
9. To measure the center window, which is typically wider, place the tape measure at the center of the joint with the left window.
10. Extend the tape measure until you reach the center of the joint with the right window.
    1. Record this width on paper.
11. Double-check all window measurements and confirm that you wrote down the measurements correctly.