This is an Excel spreadsheet to determine target thicknesses for guitar tops and backs using the method outlined in the Gore and Gillet book. It successfully duplicates the table from the book.

Although all of the input parameters are metric, it will out put the results in millimeters and inches.

In the Build volume, it shows tops being graduated thinner towards the edges. I have built one falcate steel string guitar using the target thickness, with additional graduation, and it sounds very good, indeed.