The boundary between the solar wind (SW) and the Earth’s magnetosphere, named the magnetopause (MP), is highly dynamic. Its location and shape can vary as a function of different SW parameters such as density, velocity, and interplanetary magnetic field (IMF) orientations. In the present paper an event of July 26, 2017, captured by THEMIS spacecraft is simulated by a 3D kinetic Particle-In-Cell (IAPIC) code. We investigate the impact of radial (B = Bx) and quasi-radial (Bz < Bx,By) IMF on the shape and size of Earth’s MP for a dipole tilt of 31◦ using both maximum density steepening and pressure system balance methods for identifying the boundary. We found that, compared with northward or southward-dominant IMF conditions, the MP position expands asymmetrically by 8 to 22\% under radial IMF. In addition, we construct the MP shape along the tilted magnetic equator and the OX axes showing that the expansion is asymmetric, not global, stronger on the MP flanks, and is sensitive to the ambient IMF. Finally, we investigate the contribution of SW ions back-scattered by the bow shock to the MP expansion, the temperature anisotropy in the magnetosheath, and a strong dawn-dusk asymmetry in MP location. These simulations can substantially contribute in a complementary manner with the available MHD and Hybrid models to both future space mission measurements and exoplanet magnetosphere investigations.