This thesis deals with the development of a software to calculate belt conveyors with horizontal curves, taking into consideration the forces that occur with the transport of bulk materials and their consequences on the reaction of the conveyor. An important part of the thesis is to record the forces that occur because of the turned position of the individual idlers or the whole idler platform respectively. The thus resulting horizontal bend forces are compared with the existing weights, which are taken from the net weight of the belt and the extracted materials. With the help of the drawn up software important parameter of the conveyor like the incline of the idler platform or the side-movement of the belt towards the inside of a curve when differently loaded can be calculated by comparing the components of the respective horizontal forces. In addition, the belt forces on the drive and tail pulley as well as the necessary demand power at the pulley shaft are calculated. With this software it is possible to simulate the reaction of the conveyor with varying parameter. This programme also enables an intuitive and simple parameter input and presents - almost in real time - the results clearly. Therefore a statement about the reaction of the conveyor can be made very quickly.