In summary, we have introduced the potential of electrostatics-finite ion size (PfEFIS) method, which is reliable in providing a first estimate of the magnesium jump-diffusion barrier in intercalation materials. Because PfEFIS has similar well-grounded thermodynamical foundations as reaction field theory-based prediction methods, PfEFIS provides theorectically sound electrostatic estimates of the barriers and, thus, can be used to quantitatively assess the influence of electrostatic interactions on the jump-diffusion barrier. Importantly, PfEFIS is computationally faster, typically by a factor of ≈ 10 4 (SI3), than a full nudged elastic band (NEB) calculation. When PfEFIS is coupled to an effective path finding tool, the PfEFIS framework is therefore ideally suited to efficiently perform highthroughput diffusion-barrier screenings of spherical ions such as Mg, Li, and Na intercalating into transition metal oxides and similar materials.