Joules to volts Conversion formula:
V (V) = E (in Joule) / Q (in coulombs)
Using above formula you can define the voltage (in volts) is equivalent to the energy E (in joules), divided by the charge Q (in coulombs)
So that you can rewrite formula like this:
volt (V) = joule(J) / coulomb(C)
V = J / C
The coulomb (C) is the standard unit of electric current/charge in the International System of Units (SI). Coulomb is a dimensionless quantity, like mole.
1 C is approximately equal to 6.24 x 1018 or 6.24 quintillion.