Recent experimental and theoretical studies highlight the need to predict the turbulence-induced radial diffusion of energetic particles quantitatively in present-day and future fusion devices. Gyrokinetic simulations with passive fast ion species in realistic tokamak equilibria are used to investigate the influence of the particle energy on diffusion due to electrostatic and electromagnetic turbulence. To facilitate more straightforward comparisons between theory and experiments, scaling relations are derived that allow for writing the relevant diffusivities as functions of experimentally readily accessible quantities. In this context, an improved method for estimating the magnetic fluctuation level is described.