Planar magnetic components are promising solutions for the integration of power electronic systems. The leakage inductance of such components plays an essential role in power converters. In this paper, an analytical modeling method for leakage inductance computation is developped for planar components with plasto-ferrite leakage layers. This method is based on the solution of Poisson's equations for magneto-static using multilayered Green's functions. The obtained formulations are general and precise and have been validated by numerical tests. Experimental characterizations have been performed on two magnetic components: A planar LLC and planar common mode choke. The obtained results show that with the described method, the static leakage inductance of planar components can be accurately estimated.