Has anyone come up with a way to calculate panel, stile and rail sizes easily for various sized doors?
Carol Reed: Most easily is with a computer program designed to do just that. Failing that, copy the design features of the style you like best.
Michael Dresdner: Stile and rail lengths are simple arithmetic, but what can be a challenge is figuring the panel size with any given depth of slot or dado, and picturing what width rails and stiles will look good on any given door size. For that I would suggest The Picture Frame Guide by Jerry Cole. It will help you both visualize and choose stock and setup. Though it is targeted for mitered picture frames, much of the pertinent information is the same. All you will have to do is adjust the stopped rails (or stiles, depending on your door design) by subtracting twice the width of the stock from the length.