This paper describes a highly flexible computer method for thermodynamic power cycle calculations (PCC). With this method the user can model any cycle scheme by selecting components from a library and connecting them in an appropriate way. The flexibility is not restricted by any predefined cycle schemes. A power cycle is mathematically represented by a system of algebraic equations. The structure of mathematical cycle models as well as different approaches to set up and solve the resulting equations with computer programs are discussed in the first section. The second section describes the developed method. The mass and energy balance equations are set up and solved with a semiparallel algorithm. As input only the cycle’s topology and component parameters must be entered. Information about the calculation sequence and the convergence method can be omitted completely. The example of two simple steam cycles demonstrates the applied technique. The method requires only a few, if any, iterations. Calculation time and storage requirements can be kept low enough to calculate even very complex cycles on personal computers. At the end of the paper input data and results for a complex cycle scheme as it may occur in reality are given to demonstrate the performance finally.