Rotational hardening (RH) is a specific characteristic of clay plasticity constitutive modeling describing the rotation of the yield surface (YS) in stress space during plastic loading. RH reflects macroscopically the anisotropic fabric evolution at the microstructural level of particle mechanics. For calibration purposes of RH the determination of the evolving YS in stress space under fixed stress ratio loading, is a tedious and elusive process. On the other hand, the execution of radial stress path tests (e.g. isotropic and 1D compression) while measuring the corresponding stress–dilatancy relationship, is feasible even in common commercial laboratory practice. This paper presents a methodology for the calibration of the RH based on such simple laboratory tests and on an empirical stress – dilatancy relationship.