Elastomers are extensively used in various machine design applications, mainly for vibration/shock/noise control devices. However, there are still difficulties in designing the elastomeric components applied in complex shapes and under pre-deformed states because of the complicated material properties. One of the most influential factors related to mechanical properties of elastomers are pre- and dynamic strains. Consequently, a large number of experiments have to be conducted to identify dynamic stiffness of elastomers considering their combined effects. In this paper, an efficient semi-empirical method that estimates dynamic stiffness of elastomers subjected to large static preload and small dynamic load is presented and evaluated experimentally. This method is capable of predicting the dynamic stiffness of elastomers under arbitrary compressive strain states from reduced experimental data.