In most applications using ion beams delivered by electrostatic accelerators, the accurate knowledge of the beam energy is of first importance, requiring regular beam energy calibration. The standard procedure is to use neutron thresholds and well known gamma-ray resonances for that purpose. However, only a few calibration points are available between 2 MeV and 4 MeV despite the need of such beam energies, for instance, for nuclear reaction analyses. In this work, the suitability of 27Al(p,)28Si and 45Sc(p,n)45Ti resonances has been studied for calibration in this specific energy range, by comparison with the well established calibration energies. The used methodology for the experiments and data treatment is fully detailed. The usefulness of these resonances is shown through several calibration campaigns that led to a complete energy calibration of the ion beam of two accelerator based facilities, from 500 keV to 4 MeV.