A theoretical method of determination of charge transfer is proposed. This method is based on the minimization of the total energy as a function of charge transfer. The compounds studied are in the form M(+x)(C(-x/6))6 or M(+x)(C(-x/8))8 where M represents the donor intercalate species (M = Li, K, Ca, Rb, Sr, Cs, Ba, Sm, Eu and Yb) and x the fraction of electron charge transferred from the intercalate to the graphite. The energy consists of three contributions: E(kinetic), E(potential) (coulombic+exchange) and E(Madelung). These three contributions are calculated as a function of x. The value of x giving the most stable state (minimum of energy of the compound) is defined as the charge transfer.