Refined 2D plate theories for orthotropic plates of moderate thickness are discussed. In these theories deformations, rotation and bending of the fibers and their elongations in the direction of the thickness of the shell are taken into account. The algebraic relationships for deflections and stresses, between solutions of the Kirchhoff-Love (KL) theory and the refined theories are presented. A three-dimensional mathematical model is numerically analyzed by the FEM code. Numerical results displacements and stresses determined by the presented theories are compared with the FEM results.