The possibility of the different first-principles methods to describe the chemical bonding in SrTiO₃ and SrZrO₃ cubic crystals is investigated. The local properties of the electronic structure (atomic charges, bond orders, atomic delocalization indexes, and polarization fractions) were calculated with different methods: traditional Mulliken population analysis in LCAO calculations, two projection techniques in plane-wave (PW) calculations, population analysis based on Wannier-type atomic orbitals, and chemical bonding analysis based on the localized Wannier functions for occupied (valence band) LCAO states. All the techniques considered except the traditional Mulliken analysis demonstrate that the ionicity of chemical bonding in SrZrO₃ is larger than in SrTiO₃, in agreement with the Zr and Ti electronegativities relation and the relative bandgaps observed.