The selection of toe interface parameters is important for the accuracy of numerical modeling results for reinforced soil retaining walls with hard facings. However, the shear stiffness value of toe interface can be only determined from the shear tests on concrete interfaces, which is inconvenient and time-consuming. A calculation model of the toe interface shear stiffness is proposed based on the relationship between the shear stiffness, friction angle and normal stress of the concrete-concrete interface obtained from a series of large-scale shear tests. The input parameters of the proposed calculation model are wall height and toe interface friction angle that can be obtained from a simple tilt table test. The proposed calculation model is used for providing the shear stiffness values of toe interface in the numerical simulations of three reinforced soil retaining walls with different toe restraint conditions. It is found that the calculated reinforcement strains of each wall agree well with the measured ones, and the change of the calculated reinforcement loads with toe restraint conditions is constant with the physical model test results. The above numerical results prove the feasibility of the proposed calculation model of toe interface shear stiffness.