We study numerically the switching behavior aspects and calibration effects relative to finite media embedding fully a three-dimensional ferroelectric layer in a paraelectric environment. Our approach makes use of the Ginzburg-Landau formalism in combination with the electrostatics equations. The associated discrete nonlinear system, which arises from finite element approximations, is solved by an inexact Newton method. The resulting numerical experiments highlight the effects of a balance between the physical and geometrical parameters. In particular, the same state switchings can be retrieved from different ferroelectric layer sizes by acting upon the physical characteristic of the paraelectric environment. Ferroelectric platelet samples are in parallelepipedic and cylindrical configurations involved in these experiments.