A device and method for determining the web tension or the web tensile force in a printing substrate web is disclosed. A device is arranged at a first position along a transport path of the printing substrate web, which device supplies a signal to deduce the web tension in effect at the first position or the web tensile force in effect at the first position. A device arithmetically determines the web tension in effect or the web tensile force in effect at the second position from the web tension in effect at the first position or from the web tensile force in effect at the first position as well as from forces, which at least one driven roller and/or at least one trailing roller, which is/are arranged along the transport path of the printing substrate web between the first position and the second position, introduce to the printing substrate web.