Determining the dimensions of rails and stiles:
To determine width of stile, measure from jamb to outside edge of stile on either primary window or existing storm/screen. This one measures 2 3/8″.
To determine width of bottom rail, measure from outside edge of blind stop to top of primary window bottom rail. This one measures 3 3/4″ on the inside edge (3 7/8″ on the outside edge.) It is often easier to make the rail wider and cut the bevel after the window is assembled.
For more on building wooden window screens, click here.