A computer program has been written in Fortran IV to calculate the areas of Fermi surface cross sections using the empty lattice model often referred to as the one-OPW model. The program employs the Harrison (1960) construction and will work for any structure with any Fermi radius. For hexagonal structures both the single and double zone schemes may be employed. Any plane may be selected by the user. This plane may be rotated a specified number of times about two axes and also shifted along one of the axes in order to search for extremal orbits along this axis. In applying the program to complicated Fermi surfaces a qualitative sketch of the surface may be necessary for the correct interpretation of the computer output. A copy of the deck of cards comprising the program may be obtained from the Depository of Unpublished Data.