To measure a sliding glass patio door, start by measuring the width and height of the rough opening from inside the frame. Measure at the top, middle, and bottom for width, and from both sides for height to ensure accuracy. Accurate measurements ensure the new door fits correctly, providing smooth operation and proper sealing.

Proper measurement of a sliding glass patio door is crucial for a perfect fit. Measure the width and height of the rough opening, making sure to check multiple points to ensure accuracy. This will help avoid gaps or alignment issues when installing the new door. If you're replacing an existing door, also check the track system for compatibility with the new door's size and style.