How to convert energy in electron-volts (eV) to electrical voltage in volts (V).

You can calculate volts from electron-volts and elementary charge or coulombs, but you can't convert electron-volts to volts since electron-volt and volt units represent different quantities.

eV to volts calculation with elementary charge

The voltage V in volts (V) is equal to the energy E in electron-volts (eV), divided by the electric charge Q in elementary charge or proton/electron charge (e):

V_(V) = E_(eV) / Q_(e)

The elementary charge is the electric charge of 1 electron with the e symbol.

So

volt = electronvolt / elementary charge

or

V = eV / e