The current web calculator for stopping powers is a real time implemetation of the "SRIM Module.exe" included in SRIM 2013 code (SRIM Tutorials), i.e., the current tables are those provided by SRIM code.
NOTE:
Output table includes the electronic stopping power in units of Mev cm2/g (i.e., the mass electronic stopping power).
The lower energy limit is 1 eV
The higher energy limit is 5 GeV/nucleon
In SRIM treats gas targets are dealt differently from those solid. User can select the target as gas only for elemental gas targets: H, He, N, O, F, Ne, Cl, Ar, Kr, Xe, Rn.
FINAL REMARK:
In the present electronic stopping power to dose converter, the energy lost by the incoming particle is assumed to be fully absorbed by the medium - for instance, the medium is supposed to to be thick enough to fully absorb the kinetic energy of emitted delta rays - and the particle energy is almost constant while traversing the absorber.