# GeV to kg Conversion

For GeV to kg conversion, use $E=mc^{2}$ to convert Joules to kg and then use the fact that 1 GeV is the energy required to move a charge $e$ across a potential difference of $10^{9}$ volts. Thus 1 GeV is $1.6 \times 10^{-19} \times 10^{9}$ Joules. Therefore
$m ({\rm kg}) = \frac{10^{9} \ e E({\rm GeV})}{c^{2}}$
$m ({\rm kg}) = 1.780 \times 10^{-27} \ E({\rm GeV})$
A handy thing to remember is that the proton rest mass is equivalent to $\sim 1$ GeV.