The mass of the proton, proton mass, is 1.672 621 637(83) x 10 -27 kg, or 938.272013(23) MeV/c2, or 1.007 276 466 77(10) u (that’s unified atomic mass units). The most accurate measurements of the mass of the proton come from experiments involving Penning traps, which are used to study the properties of stable charged … Continue reading Proton Mass