This calculation deals with the deflection, stress and variation of forces in the loaded flat plates. The calculation is designed for plates that are flat, homogeneous, with the same thickness and made from one material. The plates may be circular, annular circular and rectangular. The plates may be loaded evenly (unevenly) on the whole surface (or its part) or they may be loaded by the force distributed on the circle. The programme enables:- Selection from circular, annular circular or rectangular plates- Selection of various types of loading (distributed, forced...)- Calculation of deflection, slope, moment and stress in a random point- Display of graphs of the shape of the figures calculated- Calculation of safety coefficient- Calculation of the minimum plate thickness or maximum loadingThe calculation uses the data, procedures, algorithms and information from the professional literature (Roark formulas, Machinery\'s Handbook 26th, Teorie desek a skorepin [doc. Ing. Ladislav Subrt, CSc.] and others)