The cuboid actuator is presented as a simple system for evaluation of the properties of dielectric elastomer actuators. The Ogden model as a component of this theory is evaluated and parameters for VHB 4910 found in literature are compared. The model is presented and evaluated with both intensive and extensive variables. For the first time direct effects of the width prestretch on electromechanical coupling are clearly presented. Also, the importance of choosing proper parameters for the hyper-elastic model is made clear via example.