Two panel sliding glass doors can often measure: A sliding screen door kit can. pocket door width door widths pocket door widths If you have an existing door, and you are happy with the fit then we suggest that you measure this door and use these measurements for your new door. How to measure width of sliding screen door . Measure from the lowest part of the top rail as in the picture, all the way down to the top of the bottom rail. Take this measurement on the side you'll be attaching the hinges to. Then, move the measuring tape down 6 inches. If you do not have a screen to So, if you want to build your house or do some renovation, you can consider choosing any of the above sizes. To measure door width, place the tape measure tip on the inside trim edge and extend across the door to the inside trim edge on the opposite side. Measuring for a sliding screen door this page is designed to assist you in measuring for sliding screen screens. How do i measure a slid...