This paper investigates several methods for the extraction of effective elastic coefficients for integrated micro-electro-mechanical switches, to be used eventually in compact macromodels of these devices. The methods are based on the numerical results obtained from the coupled mechanical-electrostatic finite element (FE) simulation of the device. The best method found is based on a cubic least square approximation of the force-displacement characteristic extracted from the FE simulation. For this method, the relative error of the pull-in voltage is less than 0.5 % with respect to the reference value obtained from the FE simulation. The algorithm of this method is described in detail.