Hartree to mega-electron volts conversion calculator above calculates how many mega-electron volts are in 'X' Hartree (where 'X' is the number of Hartree to convert to mega-electron volts). In order to convert a value from Hartree to mega-electron volts (from Ha to MeV) type the number of Ha to be converted to MeV and then click on the 'convert' button.