The definition of Avogadro number (N ) and the current experiments to estimate it, however, both rely on the precise definition of “one gram”. Hence most of the scientists consider it as an ad-hoc number. But in reality it is not the case. In atomic and nuclear physics, atomic gravitational constant is Avogadro number times the Newton’s gravitational constant. Key conceptual link that connects the gravitational force and non-gravitational forces is - the classical force limit, ( 4 ) C F ≅ c G . Ratio of classical force limit and weak force magnitude is ( ) 2 FC FW ≅ N . Thus in this paper authors proposed many unified methods for estimating the Avogadro number.