In physics, energy measurements often utilize units like electronvolts (eV) and megaelectronvolts (MeV). An electronvolt is defined as the amount of kinetic energy gained by a single electron when it accelerates through an electric potential difference of one volt. One megaelectronvolt (MeV) is equal to one million electronvolts (eV), expressed mathematically as 1 MeV = 1,000,000 eV. To convert MeV to eV, multiply the energy value in MeV by 1,000,000. For instance, 5 MeV equals 5,000,000 eV. Conversely, to convert eV to MeV, divide the energy value in eV by 1,000,000. These conversions are essential in fields such as particle physics and nuclear physics, where precise energy measurements are crucial.