The SI unit of electric charge is the coulomb (C). One coulomb is defined as:
The charge equal to the magnitude of charge on 1 mole of protons
The charge flowing through a wire in 1 second when the current is 1 ampere (1 C=1 A⋅s)
The charge on 10¹⁹ electrons
The charge that experiences a force of 1 N when placed 1 m from an equal charge